diff --git a/internal/web/ui.go b/internal/web/ui.go
index 759b9d8..00685dd 100644
--- a/internal/web/ui.go
+++ b/internal/web/ui.go
@@ -49,6 +49,12 @@ type PageData struct {
 	ConfigStatusErr  string
 	ConfigSources    service.ConfigPreviewSources
 	ConfigPreview    *service.ConfigPreviewResult
+	ResultTitle      string
+	SelectedTemplate string
+	SelectedProfile  string
+	SelectedOverlays []string
+	SelectedConfigID string
+	SelectedVersion  string
 	Tasks            []models.Task
 	Task             *models.Task
 	Templates        []service.Template
@@ -107,6 +113,14 @@ func NewUI(discovery *service.DiscoveryService, registry *service.RegistryServic
 			b, _ := json.MarshalIndent(v, "", "  ")
 			return string(b)
 		},
+		"hasString": func(items []string, want string) bool {
+			for _, item := range items {
+				if item == want {
+					return true
+				}
+			}
+			return false
+		},
 		"ago": func(ms int64) string {
 			if ms <= 0 {
 				return "-"
@@ -873,6 +887,11 @@ func (u *UI) actionDeviceConfigPreview(w http.ResponseWriter, r *http.Request) {
 	preview, err := u.preview.Render(req)
 	data := u.configPreviewPageData(dev)
 	data.ConfigPreview = preview
+	data.SelectedTemplate = req.Template
+	data.SelectedProfile = req.Profile
+	data.SelectedOverlays = append([]string(nil), req.Overlays...)
+	data.SelectedConfigID = req.ConfigID
+	data.SelectedVersion = req.ConfigVersion
 	if err != nil {
 		data.Error = err.Error()
 	}
@@ -900,9 +919,11 @@ func (u *UI) actionDeviceConfigCandidate(w http.ResponseWriter, r *http.Request)
 		return
 	}
 	data.ConfigPreview = previewResultFromJSON(raw)
+	populateSelectionsFromPreview(&data)
 	body, code, err := u.agent.Do("PUT", dev.IP, dev.AgentPort, "/v1/config/candidate", []byte(raw))
 	data.Message = fmt.Sprintf("PUT /v1/config/candidate -> %d", code)
 	data.RawText = prettyJSON(body)
+	data.ResultTitle = "候选配置结果"
 	if err != nil {
 		data.Error = err.Error()
 	}
@@ -920,10 +941,12 @@ func (u *UI) actionDeviceConfigCandidateApply(w http.ResponseWriter, r *http.Req
 	raw := strings.TrimSpace(r.FormValue("json"))
 	if raw != "" {
 		data.ConfigPreview = previewResultFromJSON(raw)
+		populateSelectionsFromPreview(&data)
 	}
 	body, code, err := u.agent.Do("POST", dev.IP, dev.AgentPort, "/v1/config/candidate/apply", []byte(`{}`))
 	data.Message = fmt.Sprintf("POST /v1/config/candidate/apply -> %d", code)
 	data.RawText = prettyJSON(body)
+	data.ResultTitle = "应用候选配置结果"
 	if err != nil {
 		data.Error = err.Error()
 	}
@@ -932,7 +955,15 @@ func (u *UI) actionDeviceConfigCandidateApply(w http.ResponseWriter, r *http.Req
 
 func (u *UI) configPreviewPageData(dev *models.Device) PageData {
 	sources, err := u.preview.ListSources()
-	data := PageData{Title: "配置预览", Device: dev, ConfigSources: sources}
+	data := PageData{
+		Title:            "配置预览",
+		Device:           dev,
+		ConfigSources:    sources,
+		SelectedTemplate: "workshop_face_shoe_alarm",
+		SelectedProfile:  "local_3588_test",
+		SelectedOverlays: []string{"face_debug"},
+		SelectedConfigID: "preview_" + dev.DeviceID,
+	}
 	if err != nil {
 		data.Error = err.Error()
 	}
@@ -972,6 +1003,37 @@ func previewResultFromJSON(raw string) *service.ConfigPreviewResult {
 	}
 }
 
+func populateSelectionsFromPreview(data *PageData) {
+	if data == nil || data.ConfigPreview == nil {
+		return
+	}
+	if metadata := data.ConfigPreview.Metadata; metadata != nil {
+		if v, _ := metadata["template"].(string); strings.TrimSpace(v) != "" {
+			data.SelectedTemplate = v
+		}
+		if v, _ := metadata["profile"].(string); strings.TrimSpace(v) != "" {
+			data.SelectedProfile = v
+		}
+		if v, _ := metadata["config_id"].(string); strings.TrimSpace(v) != "" {
+			data.SelectedConfigID = v
+		}
+		if v, _ := metadata["config_version"].(string); strings.TrimSpace(v) != "" {
+			data.SelectedVersion = v
+		}
+		if items, ok := metadata["overlays"].([]any); ok {
+			overlays := make([]string, 0, len(items))
+			for _, item := range items {
+				if s, ok := item.(string); ok && strings.TrimSpace(s) != "" {
+					overlays = append(overlays, s)
+				}
+			}
+			if len(overlays) > 0 {
+				data.SelectedOverlays = overlays
+			}
+		}
+	}
+}
+
 func (u *UI) actionDeviceConfigUIPlan(w http.ResponseWriter, r *http.Request) {
 	id := chi.URLParam(r, "id")
 	dev, ok := u.findDevice(id)
diff --git a/internal/web/ui/templates/config_preview.html b/internal/web/ui/templates/config_preview.html
index 97b8daf..3bba19d 100644
--- a/internal/web/ui/templates/config_preview.html
+++ b/internal/web/ui/templates/config_preview.html
@@ -19,7 +19,7 @@
         <div class="muted small">模板</div>
         <select name="template">
           {{range .ConfigSources.Templates}}
-          <option value="{{.Name}}" {{if eq .Name "workshop_face_shoe_alarm"}}selected{{end}}>{{.Name}}</option>
+          <option value="{{.Name}}" {{if eq .Name $.SelectedTemplate}}selected{{end}}>{{.Name}}</option>
           {{end}}
         </select>
       </div>
@@ -27,17 +27,17 @@
         <div class="muted small">Profile</div>
         <select name="profile">
           {{range .ConfigSources.Profiles}}
-          <option value="{{.Name}}" {{if eq .Name "local_3588_test"}}selected{{end}}>{{.Name}}</option>
+          <option value="{{.Name}}" {{if eq .Name $.SelectedProfile}}selected{{end}}>{{.Name}}</option>
           {{end}}
         </select>
       </div>
       <div>
         <div class="muted small">config_id</div>
-        <input name="config_id" value="preview_{{.Device.DeviceID}}" />
+        <input name="config_id" value="{{.SelectedConfigID}}" />
       </div>
       <div>
         <div class="muted small">config_version</div>
-        <input name="config_version" placeholder="留空自动生成" />
+        <input name="config_version" value="{{.SelectedVersion}}" placeholder="留空自动生成" />
       </div>
     </div>
     <div style="margin-top:12px">
@@ -45,7 +45,7 @@
       <div class="actions" style="margin-top:6px">
         {{range .ConfigSources.Overlays}}
         <label class="btn ghost">
-          <input type="checkbox" name="overlay" value="{{.Name}}" {{if eq .Name "face_debug"}}checked{{end}} />
+          <input type="checkbox" name="overlay" value="{{.Name}}" {{if hasString $.SelectedOverlays .Name}}checked{{end}} />
           {{.Name}}
         </label>
         {{end}}
@@ -55,9 +55,7 @@
       <button type="submit">生成预览</button>
       <button type="button" disabled>上传为候选配置</button>
       {{if and .ConfigStatus .ConfigStatus.Candidate .ConfigStatus.Candidate.Exists}}
-      <form method="post" action="/ui/devices/{{.Device.DeviceID}}/config-candidate/apply" style="display:inline">
-        <button type="submit">应用候选配置</button>
-      </form>
+      <button type="submit" formaction="/ui/devices/{{.Device.DeviceID}}/config-candidate/apply">应用候选配置</button>
       {{else}}
       <button type="button" disabled>应用候选配置</button>
       {{end}}
@@ -90,13 +88,23 @@
     <button type="submit" formaction="/ui/devices/{{.Device.DeviceID}}/config-candidate/apply">应用候选配置</button>
     <a class="btn ghost" href="/ui/devices/{{.Device.DeviceID}}">查看当前运行配置</a>
   </form>
-  <pre>{{.ConfigPreview.JSON}}</pre>
+  {{if .RawText}}
+  <details>
+    <summary class="muted small">展开完整 JSON</summary>
+    <pre>{{.ConfigPreview.JSON}}</pre>
+  </details>
+  {{else}}
+  <details open>
+    <summary class="muted small">展开完整 JSON</summary>
+    <pre>{{.ConfigPreview.JSON}}</pre>
+  </details>
+  {{end}}
 </div>
 {{end}}
 
 {{if .RawText}}
 <div class="card">
-  <h2>上传结果</h2>
+  <h2>{{if .ResultTitle}}{{.ResultTitle}}{{else}}执行结果{{end}}</h2>
   <pre>{{.RawText}}</pre>
 </div>
 {{end}}
diff --git a/internal/web/ui_test.go b/internal/web/ui_test.go
index b8bb755..82373bc 100644
--- a/internal/web/ui_test.go
+++ b/internal/web/ui_test.go
@@ -364,12 +364,13 @@ func TestUI_ConfigPreviewPageKeepsApplyActionAfterUploadResult(t *testing.T) {
 			},
 			Size: 123,
 		},
-		RawText: `{"ok":true}`,
+		RawText:     `{"ok":true}`,
+		ResultTitle: "应用候选配置结果",
 	})
 
 	body := rr.Body.String()
 	for _, want := range []string{
-		"上传结果",
+		"应用候选配置结果",
 		"上传为候选配置",
 		"应用候选配置",
 		`formaction="/ui/devices/edge-01/config-candidate/apply"`,
@@ -428,7 +429,7 @@ func TestUI_ActionDeviceConfigCandidateKeepsPreviewApplyAction(t *testing.T) {
 
 	body := rr.Body.String()
 	for _, want := range []string{
-		"上传结果",
+		"候选配置结果",
 		"应用候选配置",
 		`formaction="/ui/devices/edge-01/config-candidate/apply"`,
 	} {
@@ -438,6 +439,72 @@ func TestUI_ActionDeviceConfigCandidateKeepsPreviewApplyAction(t *testing.T) {
 	}
 }
 
+func TestUI_ConfigPreviewKeepsSelectedOverlayAfterPreview(t *testing.T) {
+	ui := newTestUI(t)
+	req := httptest.NewRequest(http.MethodGet, "/ui/devices/edge-01/config-preview", nil)
+	rr := httptest.NewRecorder()
+
+	ui.render(rr, req, "config_preview", PageData{
+		Title:            "配置预览",
+		Device:           &models.Device{DeviceID: "edge-01", DeviceName: "入口识别节点", IP: "127.0.0.1", AgentPort: 9100},
+		ConfigSources:    service.ConfigPreviewSources{Templates: []service.ConfigSource{{Name: "workshop_face_shoe_alarm"}}, Profiles: []service.ConfigSource{{Name: "local_3588_test"}}, Overlays: []service.ConfigSource{{Name: "face_debug"}, {Name: "face_test_sensitive"}}},
+		SelectedTemplate: "workshop_face_shoe_alarm",
+		SelectedProfile:  "local_3588_test",
+		SelectedOverlays: []string{"face_test_sensitive"},
+		SelectedConfigID: "preview_edge-01",
+		ConfigPreview: &service.ConfigPreviewResult{
+			JSON: `{"templates":{"tpl":{"nodes":[],"edges":[]}},"instances":[],"metadata":{"config_id":"preview_edge-01","config_version":"v1","template":"workshop_face_shoe_alarm","profile":"local_3588_test","overlays":["face_test_sensitive"]}}`,
+			Metadata: map[string]any{
+				"config_id":      "preview_edge-01",
+				"config_version": "v1",
+				"template":       "workshop_face_shoe_alarm",
+				"profile":        "local_3588_test",
+				"overlays":       []any{"face_test_sensitive"},
+			},
+			Size: 123,
+		},
+	})
+
+	body := rr.Body.String()
+	if !strings.Contains(body, `value="face_test_sensitive" checked`) {
+		t.Fatalf("expected selected overlay to remain checked, got:\n%s", body)
+	}
+	if strings.Contains(body, `value="face_debug" checked`) {
+		t.Fatalf("did not expect default overlay to stay checked, got:\n%s", body)
+	}
+}
+
+func TestUI_ConfigPreviewCollapsesJSONAfterActionResult(t *testing.T) {
+	ui := newTestUI(t)
+	req := httptest.NewRequest(http.MethodGet, "/ui/devices/edge-01/config-preview", nil)
+	rr := httptest.NewRecorder()
+
+	ui.render(rr, req, "config_preview", PageData{
+		Title:            "配置预览",
+		Device:           &models.Device{DeviceID: "edge-01", DeviceName: "入口识别节点", IP: "127.0.0.1", AgentPort: 9100},
+		ConfigSources:    service.ConfigPreviewSources{Templates: []service.ConfigSource{{Name: "workshop_face_shoe_alarm"}}, Profiles: []service.ConfigSource{{Name: "local_3588_test"}}, Overlays: []service.ConfigSource{{Name: "face_debug"}}},
+		SelectedTemplate: "workshop_face_shoe_alarm",
+		SelectedProfile:  "local_3588_test",
+		SelectedOverlays: []string{"face_debug"},
+		SelectedConfigID: "preview_edge-01",
+		ConfigPreview: &service.ConfigPreviewResult{
+			JSON:     `{"templates":{"tpl":{"nodes":[],"edges":[]}},"instances":[]}`,
+			Metadata: map[string]any{"config_id": "preview_edge-01"},
+			Size:     64,
+		},
+		ResultTitle: "候选配置结果",
+		RawText:     `{"ok":true}`,
+	})
+
+	body := rr.Body.String()
+	if !strings.Contains(body, "<details") {
+		t.Fatalf("expected json panel to use details, got:\n%s", body)
+	}
+	if strings.Contains(body, "<details open>") {
+		t.Fatalf("expected json panel to be collapsed after action result, got:\n%s", body)
+	}
+}
+
 func TestUI_ModelDeploymentPageRendersDeviceActions(t *testing.T) {
 	ui := newTestUI(t)
 	req := httptest.NewRequest(http.MethodGet, "/ui/models", nil)