diff --git a/internal/common/errors.go b/internal/common/errors.go
index 571c778..c9793e0 100644
--- a/internal/common/errors.go
+++ b/internal/common/errors.go
@@ -35,4 +35,12 @@ var (
 	ErrNeedsConfirmRestore  = errors.New("需要二次确认恢复账号")
 	ErrOwnerCannotDelete    = errors.New("站长不可自主注销，请先转让站长权限")
 	ErrRegistrationDisabled = errors.New("注册功能已关闭")
+
+	// 帖子相关
+	ErrPostNotFound      = errors.New("帖子不存在")
+	ErrPostCannotEdit    = errors.New("当前状态不允许编辑")
+	ErrPostCannotSubmit  = errors.New("仅草稿和已退回帖子可提交审核")
+	ErrPostCannotApprove = errors.New("仅待审核帖子可通过")
+	ErrPostCannotReject  = errors.New("仅待审核和已发布帖子可退回")
+	ErrPostCannotUnlock  = errors.New("仅锁定状态可解锁")
 )
diff --git a/internal/controller/admin/admin_post_controller.go b/internal/controller/admin/admin_post_controller.go
index 64ae5f9..919ac14 100644
--- a/internal/controller/admin/admin_post_controller.go
+++ b/internal/controller/admin/admin_post_controller.go
@@ -1,6 +1,7 @@
 package admin
 
 import (
+	"errors"
 	"net/http"
 	"strconv"
 
@@ -72,7 +73,11 @@ func (ctrl *AdminPostController) Approve(c *gin.Context) {
 	}
 
 	if err := ctrl.postService.Approve(uint(id)); err != nil {
-		common.Error(c, http.StatusBadRequest, err.Error())
+		if errors.Is(err, common.ErrPostCannotApprove) || errors.Is(err, common.ErrPostNotFound) {
+			common.Error(c, http.StatusBadRequest, err.Error())
+		} else {
+			common.Error(c, http.StatusInternalServerError, "审核失败")
+		}
 		return
 	}
 
@@ -94,7 +99,11 @@ func (ctrl *AdminPostController) Reject(c *gin.Context) {
 	}
 
 	if err := ctrl.postService.Reject(uint(id), req.Reason); err != nil {
-		common.Error(c, http.StatusBadRequest, err.Error())
+		if errors.Is(err, common.ErrPostCannotReject) || errors.Is(err, common.ErrPostNotFound) {
+			common.Error(c, http.StatusBadRequest, err.Error())
+		} else {
+			common.Error(c, http.StatusInternalServerError, "退回失败")
+		}
 		return
 	}
 
@@ -110,7 +119,11 @@ func (ctrl *AdminPostController) Lock(c *gin.Context) {
 	}
 
 	if err := ctrl.postService.Lock(uint(id)); err != nil {
-		common.Error(c, http.StatusBadRequest, err.Error())
+		if errors.Is(err, common.ErrPostNotFound) {
+			common.Error(c, http.StatusBadRequest, err.Error())
+		} else {
+			common.Error(c, http.StatusInternalServerError, "锁定失败")
+		}
 		return
 	}
 
@@ -126,7 +139,11 @@ func (ctrl *AdminPostController) Unlock(c *gin.Context) {
 	}
 
 	if err := ctrl.postService.Unlock(uint(id)); err != nil {
-		common.Error(c, http.StatusBadRequest, err.Error())
+		if errors.Is(err, common.ErrPostCannotUnlock) || errors.Is(err, common.ErrPostNotFound) {
+			common.Error(c, http.StatusBadRequest, err.Error())
+		} else {
+			common.Error(c, http.StatusInternalServerError, "解锁失败")
+		}
 		return
 	}
 
@@ -142,7 +159,7 @@ func (ctrl *AdminPostController) Restore(c *gin.Context) {
 	}
 
 	if err := ctrl.postService.Restore(uint(id)); err != nil {
-		common.Error(c, http.StatusBadRequest, err.Error())
+		common.Error(c, http.StatusInternalServerError, "恢复失败")
 		return
 	}
 
diff --git a/internal/controller/post_controller.go b/internal/controller/post_controller.go
index d42e131..df14921 100644
--- a/internal/controller/post_controller.go
+++ b/internal/controller/post_controller.go
@@ -1,6 +1,7 @@
 package controller
 
 import (
+	"errors"
 	"fmt"
 	"html/template"
 	"mime/multipart"
@@ -144,6 +145,22 @@ func (ctrl *PostController) EditPage(c *gin.Context) {
 		return
 	}
 
+	// 权限检查：仅作者和 moderator+ 可编辑
+	var uid uint
+	var role string
+	if uidObj, exists := c.Get("uid"); exists {
+		uid, _ = uidObj.(uint)
+	}
+	if roleObj, exists := c.Get("role"); exists {
+		role, _ = roleObj.(string)
+	}
+	if post.UserID != uid && !model.HasMinRole(role, model.RoleModerator) {
+		c.HTML(http.StatusNotFound, "posts/404.html", common.BuildPageData(c, gin.H{
+			"Title": "未找到",
+		}))
+		return
+	}
+
 	c.HTML(http.StatusOK, "posts/new.html", common.BuildPageData(c, gin.H{
 		"Title":    "编辑帖子",
 		"Post":     post,
@@ -178,7 +195,11 @@ func (ctrl *PostController) Create(c *gin.Context) {
 // Update API 编辑帖子
 func (ctrl *PostController) Update(c *gin.Context) {
 	uidObj, _ := c.Get("uid")
-	uid, _ := uidObj.(uint)
+	uid, ok := uidObj.(uint)
+	if !ok {
+		common.Error(c, http.StatusUnauthorized, "请先登录")
+		return
+	}
 
 	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
 	if err != nil {
@@ -206,7 +227,11 @@ func (ctrl *PostController) Update(c *gin.Context) {
 	}
 
 	if err := ctrl.postService.Update(uint(id), req.Title, req.Body); err != nil {
-		common.Error(c, http.StatusBadRequest, err.Error())
+		if errors.Is(err, common.ErrPostCannotEdit) {
+			common.Error(c, http.StatusBadRequest, err.Error())
+		} else {
+			common.Error(c, http.StatusInternalServerError, "编辑失败")
+		}
 		return
 	}
 
@@ -216,7 +241,11 @@ func (ctrl *PostController) Update(c *gin.Context) {
 // Delete API 删除帖子
 func (ctrl *PostController) Delete(c *gin.Context) {
 	uidObj, _ := c.Get("uid")
-	uid, _ := uidObj.(uint)
+	uid, ok := uidObj.(uint)
+	if !ok {
+		common.Error(c, http.StatusUnauthorized, "请先登录")
+		return
+	}
 
 	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
 	if err != nil {
@@ -254,7 +283,11 @@ func (ctrl *PostController) Submit(c *gin.Context) {
 	}
 
 	if err := ctrl.postService.SubmitForAudit(uint(id)); err != nil {
-		common.Error(c, http.StatusBadRequest, err.Error())
+		if errors.Is(err, common.ErrPostCannotSubmit) || errors.Is(err, common.ErrPostNotFound) {
+			common.Error(c, http.StatusBadRequest, err.Error())
+		} else {
+			common.Error(c, http.StatusInternalServerError, "提交审核失败")
+		}
 		return
 	}
 
@@ -303,6 +336,24 @@ func (ctrl *PostController) ShowAPI(c *gin.Context) {
 		return
 	}
 
+	// 权限控制：非 approved 帖子仅作者和 moderator+ 可见
+	if post.Status != model.PostStatusApproved {
+		var uid uint
+		var role string
+		if uidObj, exists := c.Get("uid"); exists {
+			uid, _ = uidObj.(uint)
+		}
+		if roleObj, exists := c.Get("role"); exists {
+			role, _ = roleObj.(string)
+		}
+		isAuthor := uid == post.UserID
+		isModerator := model.HasMinRole(role, model.RoleModerator)
+		if !isAuthor && !isModerator {
+			common.Error(c, http.StatusNotFound, "帖子不存在")
+			return
+		}
+	}
+
 	common.Ok(c, post)
 }
 
diff --git a/internal/service/post_service.go b/internal/service/post_service.go
index 9edf841..f396eda 100644
--- a/internal/service/post_service.go
+++ b/internal/service/post_service.go
@@ -1,6 +1,7 @@
 package service
 
 import (
+	"errors"
 	"fmt"
 	"regexp"
 
@@ -9,6 +10,7 @@ import (
 	"metazone.cc/metalab/internal/model"
 
 	"github.com/microcosm-cc/bluemonday"
+	"gorm.io/gorm"
 )
 
 // sanitizePolicy Tiptap 输出 HTML 的消毒策略
@@ -24,18 +26,6 @@ var sanitizePolicy = func() *bluemonday.Policy {
 	return p
 }()
 
-// postStore 帖子服务所需的最小仓储接口（ISP）
-type postStore interface {
-	Create(post *model.Post) error
-	FindByID(id uint) (*model.Post, error)
-	FindByIDWithAuthor(id uint) (*model.Post, error)
-	FindPageable(keyword string, offset, limit int) ([]model.Post, int64, error)
-	FindAdminPageable(keyword, status string, offset, limit int) ([]model.Post, int64, error)
-	Update(post *model.Post) error
-	SoftDelete(id uint) error
-	Restore(id uint) error
-}
-
 // PostService 帖子业务逻辑
 type PostService struct {
 	repo postStore
@@ -55,6 +45,30 @@ func (s *PostService) auditEnabled() bool {
 	return s.ss.IsAuditEnabled()
 }
 
+// findPost 按 ID 查找帖子，区分"未找到"和"数据库错误"
+func (s *PostService) findPost(id uint) (*model.Post, error) {
+	post, err := s.repo.FindByID(id)
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, common.ErrPostNotFound
+		}
+		return nil, fmt.Errorf("查询帖子失败: %w", err)
+	}
+	return post, nil
+}
+
+// findPostWithAuthor 按 ID 查找帖子（含作者名），区分"未找到"和"数据库错误"
+func (s *PostService) findPostWithAuthor(id uint) (*model.Post, error) {
+	post, err := s.repo.FindByIDWithAuthor(id)
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, common.ErrPostNotFound
+		}
+		return nil, fmt.Errorf("查询帖子失败: %w", err)
+	}
+	return post, nil
+}
+
 // sanitizeHTML 对 Tiptap 输出的 HTML 进行消毒
 // 前端 WYSIWYG 编辑器直接输出 HTML，后端仅做安全消毒
 func (s *PostService) sanitizeHTML(body string) string {
@@ -86,11 +100,7 @@ func (s *PostService) Create(userID uint, title, body string) (*model.Post, erro
 
 // GetByID 按 ID 获取帖子（含作者名，仅 approved 公开可见）
 func (s *PostService) GetByID(id uint) (*model.Post, error) {
-	post, err := s.repo.FindByIDWithAuthor(id)
-	if err != nil {
-		return nil, common.ErrUserNotFound // 复用哨兵表示资源不存在
-	}
-	return post, nil
+	return s.findPostWithAuthor(id)
 }
 
 // List 公开帖子列表（仅 approved）
@@ -109,13 +119,13 @@ func (s *PostService) ListAdmin(keyword, status string, page, pageSize int) ([]m
 
 // Update 编辑帖子（权限在 controller 层检查）
 func (s *PostService) Update(postID uint, title, body string) error {
-	post, err := s.repo.FindByID(postID)
+	post, err := s.findPost(postID)
 	if err != nil {
-		return common.ErrUserNotFound
+		return err
 	}
 
 	if post.Status == model.PostStatusPending || post.Status == model.PostStatusLocked {
-		return fmt.Errorf("当前状态不允许编辑")
+		return common.ErrPostCannotEdit
 	}
 
 	post.Title = title
@@ -138,12 +148,12 @@ func (s *PostService) Delete(postID uint) error {
 
 // SubmitForAudit 提交审核：draft → pending
 func (s *PostService) SubmitForAudit(postID uint) error {
-	post, err := s.repo.FindByID(postID)
+	post, err := s.findPost(postID)
 	if err != nil {
-		return common.ErrUserNotFound
+		return err
 	}
 	if post.Status != model.PostStatusDraft && post.Status != model.PostStatusRejected {
-		return fmt.Errorf("仅草稿和已退回帖子可提交审核")
+		return common.ErrPostCannotSubmit
 	}
 	post.Status = model.PostStatusPending
 	return s.repo.Update(post)
@@ -151,12 +161,12 @@ func (s *PostService) SubmitForAudit(postID uint) error {
 
 // Approve 审核通过：pending → approved
 func (s *PostService) Approve(postID uint) error {
-	post, err := s.repo.FindByID(postID)
+	post, err := s.findPost(postID)
 	if err != nil {
-		return common.ErrUserNotFound
+		return err
 	}
 	if post.Status != model.PostStatusPending {
-		return fmt.Errorf("仅待审核帖子可通过")
+		return common.ErrPostCannotApprove
 	}
 	post.Status = model.PostStatusApproved
 	post.RejectReason = ""
@@ -165,23 +175,23 @@ func (s *PostService) Approve(postID uint) error {
 
 // Reject 退回：pending/approved → rejected
 func (s *PostService) Reject(postID uint, reason string) error {
-	post, err := s.repo.FindByID(postID)
+	post, err := s.findPost(postID)
 	if err != nil {
-		return common.ErrUserNotFound
+		return err
 	}
 	if post.Status != model.PostStatusPending && post.Status != model.PostStatusApproved {
-		return fmt.Errorf("仅待审核和已发布帖子可退回")
+		return common.ErrPostCannotReject
 	}
 	post.Status = model.PostStatusRejected
 	post.RejectReason = reason
 	return s.repo.Update(post)
 }
 
-// Lock 锁定：任意状态 → locked
+// Lock 锁定：任意状态 → locked（管理员可随时锁定）
 func (s *PostService) Lock(postID uint) error {
-	post, err := s.repo.FindByID(postID)
+	post, err := s.findPost(postID)
 	if err != nil {
-		return common.ErrUserNotFound
+		return err
 	}
 	post.Status = model.PostStatusLocked
 	return s.repo.Update(post)
@@ -189,12 +199,12 @@ func (s *PostService) Lock(postID uint) error {
 
 // Unlock 解锁：locked → 草稿
 func (s *PostService) Unlock(postID uint) error {
-	post, err := s.repo.FindByID(postID)
+	post, err := s.findPost(postID)
 	if err != nil {
-		return common.ErrUserNotFound
+		return err
 	}
 	if post.Status != model.PostStatusLocked {
-		return fmt.Errorf("仅锁定状态可解锁")
+		return common.ErrPostCannotUnlock
 	}
 	post.Status = model.PostStatusDraft
 	return s.repo.Update(post)
diff --git a/internal/service/repository.go b/internal/service/repository.go
index e1a0c8b..6c4c2a5 100644
--- a/internal/service/repository.go
+++ b/internal/service/repository.go
@@ -31,5 +31,14 @@ type userAdminStore interface {
 	IncrementTokenVersion(userID uint) error
 }
 
-
-
+// postStore PostService 所需的最小仓储接口（ISP：8 个方法）
+type postStore interface {
+	Create(post *model.Post) error
+	FindByID(id uint) (*model.Post, error)
+	FindByIDWithAuthor(id uint) (*model.Post, error)
+	FindPageable(keyword string, offset, limit int) ([]model.Post, int64, error)
+	FindAdminPageable(keyword, status string, offset, limit int) ([]model.Post, int64, error)
+	Update(post *model.Post) error
+	SoftDelete(id uint) error
+	Restore(id uint) error
+}
\ No newline at end of file
diff --git a/templates/MetaLab-2026/html/posts/new.html b/templates/MetaLab-2026/html/posts/new.html
index c32cba0..4664828 100644
--- a/templates/MetaLab-2026/html/posts/new.html
+++ b/templates/MetaLab-2026/html/posts/new.html
@@ -282,4 +282,3 @@
 </script>
 <script src="/static/js/common.js"></script>
 <script type="module" src="/static/js/editor.js"></script>
-</template>