diff --git a/internal/web/ui.go b/internal/web/ui.go
index 5d14ce7..7476b02 100644
--- a/internal/web/ui.go
+++ b/internal/web/ui.go
@@ -1049,7 +1049,7 @@ func (u *UI) pageLogs(w http.ResponseWriter, r *http.Request) {
 }
 
 func (u *UI) pageAPIConsole(w http.ResponseWriter, r *http.Request) {
-	http.Redirect(w, r, "/ui/system", http.StatusFound)
+	u.render(w, r, "api", PageData{Title: "高级调试"})
 }
 
 func (u *UI) pageAssets(w http.ResponseWriter, r *http.Request) {
@@ -1259,11 +1259,11 @@ func (u *UI) pageAudit(w http.ResponseWriter, r *http.Request) {
 	if u.tasks != nil {
 		tasks = u.tasks.ListTasks()
 	}
-	u.render(w, r, "audit", PageData{Title: "操作审计", Tasks: tasks})
+	u.render(w, r, "audit", PageData{Title: "审计记录", Tasks: tasks})
 }
 
 func (u *UI) pageSystem(w http.ResponseWriter, r *http.Request) {
-	u.render(w, r, "system", PageData{Title: "系统", Devices: u.registry.GetDevices()})
+	u.render(w, r, "system", PageData{Title: "系统状态", Devices: u.registry.GetDevices()})
 }
 
 func urlQueryEscape(s string) string {
diff --git a/internal/web/ui/templates/api.html b/internal/web/ui/templates/api.html
index 629783a..920b72a 100644
--- a/internal/web/ui/templates/api.html
+++ b/internal/web/ui/templates/api.html
@@ -1,5 +1,6 @@
 {{define "api"}}
 <div class="card">
+  <div class="crumb">诊断 / 高级调试</div>
   <h2>高级调试</h2>
 </div>
 
diff --git a/internal/web/ui/templates/audit.html b/internal/web/ui/templates/audit.html
index a868d13..a46612b 100644
--- a/internal/web/ui/templates/audit.html
+++ b/internal/web/ui/templates/audit.html
@@ -2,6 +2,7 @@
 <div class="card">
   <div class="section-title">
     <div>
+      <div class="crumb">诊断 / 审计记录</div>
       <h2 class="title-with-icon">{{icon "audit"}}<span>审计记录</span></h2>
     </div>
   </div>
diff --git a/internal/web/ui/templates/system.html b/internal/web/ui/templates/system.html
index 9d8ddbe..e84a074 100644
--- a/internal/web/ui/templates/system.html
+++ b/internal/web/ui/templates/system.html
@@ -1,4 +1,9 @@
 {{define "system"}}
+<div class="card">
+  <div class="crumb">诊断 / 系统状态</div>
+  <div class="muted small" style="margin-top:8px">系统状态页负责平台健康、发现机制和接入策略查看。</div>
+</div>
+
 <div class="detail-grid">
   <div class="card">
     <h2 class="title-with-icon">{{icon "discovery"}}<span>设备发现与注册</span></h2>
diff --git a/internal/web/ui_test.go b/internal/web/ui_test.go
index 2ee04da..3121fb5 100644
--- a/internal/web/ui_test.go
+++ b/internal/web/ui_test.go
@@ -2186,3 +2186,21 @@ func TestUI_TaskDetailPresentsExecutionSections(t *testing.T) {
 		}
 	}
 }
+
+func TestUI_DiagnosticsSecondaryPagesUseDiagnosticsCrumb(t *testing.T) {
+	ui := newTestUI(t)
+
+	for _, item := range []struct {
+		path string
+		want string
+	}{
+		{path: "/ui/system", want: "诊断 / 系统状态"},
+		{path: "/ui/audit", want: "诊断 / 审计记录"},
+		{path: "/ui/api", want: "诊断 / 高级调试"},
+	} {
+		html := renderPage(t, ui, item.path)
+		if !strings.Contains(html, item.want) {
+			t.Fatalf("expected %s to contain crumb %q, got: %s", item.path, item.want, html)
+		}
+	}
+}