diff --git a/internal/session/manager.go b/internal/session/manager.go
index 3123a50..f36a7fe 100644
--- a/internal/session/manager.go
+++ b/internal/session/manager.go
@@ -79,6 +79,11 @@ func (m *Manager) Validate(sid string) (*Session, error) {
 		return nil, nil
 	}
 
+	// 同步 DB 最新字段（头像/用户名/角色等可能已变更）
+	s.Avatar = user.Avatar
+	s.Username = user.Username
+	s.Role = user.Role
+
 	// 滑动窗口续期
 	s.Touch()
 	if err := m.store.Set(s); err != nil {
diff --git a/templates/MetaLab-2026/html/layout/nav.html b/templates/MetaLab-2026/html/layout/nav.html
index d4650b6..b0f0384 100644
--- a/templates/MetaLab-2026/html/layout/nav.html
+++ b/templates/MetaLab-2026/html/layout/nav.html
@@ -20,7 +20,8 @@
             <li class="nav-avatar-wrapper">
                 <a href="/space" class="nav-avatar-link">
                     {{if .Avatar}}
-                    <img src="{{.Avatar}}" alt="" class="nav-avatar">
+                    <img src="{{.Avatar}}" alt="" class="nav-avatar" onerror="this.style.display='none';this.nextElementSibling.style.display='flex'">
+                    <span class="nav-avatar nav-avatar-default" style="display:none">{{substr .Username 0 1}}</span>
                     {{else}}
                     <span class="nav-avatar nav-avatar-default">{{substr .Username 0 1}}</span>
                     {{end}}