diff --git a/Fableon/Object/Libs/Alert/FAPayRetainAlert.swift b/Fableon/Object/Libs/Alert/FAPayRetainAlert.swift
index 9b5ba20..1a34f8d 100644
--- a/Fableon/Object/Libs/Alert/FAPayRetainAlert.swift
+++ b/Fableon/Object/Libs/Alert/FAPayRetainAlert.swift
@@ -166,6 +166,7 @@ extension FAPayRetainAlert {
         }
 
         private static let defaultCountdownSeconds = 4 * 60 * 60
+        private static let countdownEndTimeKey = "FAPayRetainCountdownEndTime"
         private var countdownTimer: Timer?
         private var remainingSeconds: Int = 0
 
@@ -252,8 +253,12 @@ extension FAPayRetainAlert {
         // 每次展示时从 4 小时开始倒计时
         private func startCountdown() {
             stopCountdown()
-            remainingSeconds = Self.defaultCountdownSeconds
+            let endTime = resolveEndTime()
+            remainingSeconds = max(0, Int(endTime - Date().timeIntervalSince1970))
             updateTimeLabels()
+            guard remainingSeconds > 0 else {
+                return
+            }
             countdownTimer = Timer.scheduledTimer(timeInterval: 1,
                                                   target: YYTextWeakProxy(target: self),
                                                   selector: #selector(handleCountdownTimer),
@@ -276,6 +281,18 @@ extension FAPayRetainAlert {
             updateTimeLabels()
         }
 
+        private func resolveEndTime() -> TimeInterval {
+            let defaults = UserDefaults.standard
+            let now = Date().timeIntervalSince1970
+            let storedEndTime = defaults.double(forKey: Self.countdownEndTimeKey)
+            if storedEndTime > now {
+                return storedEndTime
+            }
+            let newEndTime = now + TimeInterval(Self.defaultCountdownSeconds)
+            defaults.set(newEndTime, forKey: Self.countdownEndTimeKey)
+            return newEndTime
+        }
+
         private func updateTimeLabels() {
             let hours = remainingSeconds / 3600
             let minutes = (remainingSeconds % 3600) / 60