diff --git a/internal/service/alarm_collector.go b/internal/service/alarm_collector.go
index 593c51c..69a2b06 100644
--- a/internal/service/alarm_collector.go
+++ b/internal/service/alarm_collector.go
@@ -56,6 +56,13 @@ func (c *AlarmCollector) SetRetention(days int) {
     c.retentionDays = days
 }
 
+func (c *AlarmCollector) GetRetention() int {
+    if c == nil {
+        return 30
+    }
+    return c.retentionDays
+}
+
 func (c *AlarmCollector) cleanupLoop() {
     c.cleanupOldAlarms()
     ticker := time.NewTicker(24 * time.Hour)
diff --git a/internal/web/ui.go b/internal/web/ui.go
index 6daab68..c380ae1 100644
--- a/internal/web/ui.go
+++ b/internal/web/ui.go
@@ -111,6 +111,8 @@ type PageData struct {
     UnacknowledgedAlarmCount int
     DetectionChannelCount    int
     StaleCount               int
+    SystemAlarmRetention     int
+    SystemConcurrency        int
     AlarmFilterDevices       []string
     AlarmFilterRuleTypes     []string
     SelectedAlarmDevice      string
@@ -793,6 +795,7 @@ func (u *UI) Routes() (chi.Router, error) {
     r.Get("/assets/overlays/{name}/export", u.pageAssetOverlayExport)
     r.Get("/audit", u.pageAudit)
     r.Get("/system", u.pageSystem)
+    r.Post("/system/config", u.actionSystemConfig)
     r.Get("/system/db-backup", u.pageSystemDBBackup)
     r.Get("/resources", u.pageResources)
     r.Post("/system/db-restore", u.actionSystemDBRestore)
@@ -4258,13 +4261,36 @@ func (u *UI) pageSystemDBBackup(w http.ResponseWriter, r *http.Request) {
 
 func (u *UI) renderSystemPage(w http.ResponseWriter, r *http.Request, status int, message string, errText string) {
     w.WriteHeader(status)
-    u.render(w, r, "system", PageData{
-        Title:   "系统状态",
-        Devices: u.registry.GetDevices(),
-        DBPath:  u.dbPath,
-        Message: message,
-        Error:   errText,
-    })
+    data := PageData{
+        Title:              "系统状态",
+        Devices:            u.registry.GetDevices(),
+        DBPath:             u.dbPath,
+        Message:            message,
+        Error:              errText,
+        SystemAlarmRetention: 30,
+        SystemConcurrency:    5,
+    }
+    if u.alarmCollector != nil {
+        data.SystemAlarmRetention = u.alarmCollector.GetRetention()
+    }
+    u.render(w, r, "system", data)
+}
+
+func (u *UI) actionSystemConfig(w http.ResponseWriter, r *http.Request) {
+    _ = r.ParseForm()
+    if days, err := strconv.Atoi(strings.TrimSpace(r.FormValue("alarm_retention_days"))); err == nil && days >= 0 {
+        if u.alarmCollector != nil {
+            u.alarmCollector.SetRetention(days)
+        }
+        msg := "告警保留已设为 " + strconv.Itoa(days) + " 天"
+        if days == 0 {
+            msg = "告警将永久保留"
+        }
+        msg += "（运行时生效，重启后需在配置文件 safesightd.json 中修改 alarm_retention_days 持久化）"
+        u.renderSystemPage(w, r, http.StatusOK, msg, "")
+        return
+    }
+    u.renderSystemPage(w, r, http.StatusBadRequest, "", "请输入有效的保留天数")
 }
 
 func (u *UI) actionSystemDBRestore(w http.ResponseWriter, r *http.Request) {
diff --git a/internal/web/ui/templates/system.html b/internal/web/ui/templates/system.html
index 8e55d4e..8dda8e2 100644
--- a/internal/web/ui/templates/system.html
+++ b/internal/web/ui/templates/system.html
@@ -36,6 +36,20 @@
   </div>
 </div>
 
+<div class="detail-grid">
+  <div class="card">
+    <h2 class="title-with-icon">{{icon "system"}}<span>系统配置</span></h2>
+    <form method="post" action="/system/config">
+      <div class="field-grid">
+        <label><span>告警保留天数</span><input type="number" name="alarm_retention_days" value="{{.SystemAlarmRetention}}" min="0" /><div class="form-hint">0=永久保留</div></label>
+      </div>
+      <div class="actions" style="margin-top:12px">
+        <button type="submit" class="secondary">保存配置</button>
+      </div>
+    </form>
+  </div>
+</div>
+
 <script>
 (function() {
   var svcEl = document.getElementById("svc-status");
diff --git a/safesightd-linux-arm64 b/safesightd-linux-arm64
index 198bc75..5ea75d5 100644
Binary files a/safesightd-linux-arm64 and b/safesightd-linux-arm64 differ