diff --git a/suixinkan/SceneDelegate.swift b/suixinkan/SceneDelegate.swift
index 598975b..95bac71 100644
--- a/suixinkan/SceneDelegate.swift
+++ b/suixinkan/SceneDelegate.swift
@@ -8,6 +8,7 @@ import UIKit
 class SceneDelegate: UIResponder, UIWindowSceneDelegate {
 
     var window: UIWindow?
+    private var sessionExpiredDialog: SessionExpiredDialogViewController?
 
     func scene(
         _ scene: UIScene,
@@ -86,18 +87,36 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
     }
 
     @objc private func handleSessionDidExpire() {
+        guard AppStore.shared.session.isLoggedIn else { return }
+        guard sessionExpiredDialog == nil else { return }
+
+        GlobalLoadingManager.shared.hideAll()
+        let dialog = SessionExpiredDialogViewController { [weak self] in
+            self?.transitionToLogin()
+        }
+        sessionExpiredDialog = dialog
+
+        guard let presenter = topViewController(from: window?.rootViewController) else {
+            sessionExpiredDialog = nil
+            return
+        }
+        presenter.present(dialog, animated: true)
+    }
+
+    private func transitionToLogin() {
+        sessionExpiredDialog = nil
         PushNotificationManager.shared.handleLogout()
         AppStore.shared.logout()
         AppRouter.setRoot(.login, on: window)
     }
 
     @objc private func handleUserDidLogout() {
-        PushNotificationManager.shared.handleLogout()
-        AppStore.shared.logout()
-        AppRouter.setRoot(.login, on: window)
+        transitionToLogin()
     }
 
     @objc private func handleUserDidLogin() {
+        sessionExpiredDialog?.dismiss(animated: false)
+        sessionExpiredDialog = nil
         AppRouter.setRoot(.mainTab, on: window)
         DispatchQueue.main.async {
             PushNotificationManager.shared.handleLoginCompleted()
@@ -108,4 +127,18 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
     @objc private func handleAccountDidSwitch() {
         PushNotificationManager.shared.handleAccountSwitched()
     }
+
+    private func topViewController(from viewController: UIViewController?) -> UIViewController? {
+        guard let viewController else { return nil }
+        if let presented = viewController.presentedViewController {
+            return topViewController(from: presented)
+        }
+        if let navigationController = viewController as? UINavigationController {
+            return topViewController(from: navigationController.visibleViewController)
+        }
+        if let tabBarController = viewController as? UITabBarController {
+            return topViewController(from: tabBarController.selectedViewController)
+        }
+        return viewController
+    }
 }
diff --git a/suixinkan/UI/Common/SessionExpiredDialogViewController.swift b/suixinkan/UI/Common/SessionExpiredDialogViewController.swift
new file mode 100644
index 0000000..138e1d5
--- /dev/null
+++ b/suixinkan/UI/Common/SessionExpiredDialogViewController.swift
@@ -0,0 +1,103 @@
+//
+//  SessionExpiredDialogViewController.swift
+//  suixinkan
+//
+
+import SnapKit
+import UIKit
+
+/// 登录凭证失效时展示的强制确认弹窗，用户确认后由调用方执行退出登录。
+@MainActor
+final class SessionExpiredDialogViewController: UIViewController {
+
+    private let onConfirm: () -> Void
+    private let confirmButton = AppButton(title: "确认并退出登录")
+    private var didConfirm = false
+
+    /// 创建不可通过点击遮罩关闭的登录失效弹窗。
+    init(onConfirm: @escaping () -> Void) {
+        self.onConfirm = onConfirm
+        super.init(nibName: nil, bundle: nil)
+        modalPresentationStyle = .overFullScreen
+        modalTransitionStyle = .crossDissolve
+        isModalInPresentation = true
+    }
+
+    @available(*, unavailable)
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        setupUI()
+    }
+
+    private func setupUI() {
+        view.backgroundColor = UIColor.black.withAlphaComponent(0.32)
+        view.accessibilityViewIsModal = true
+        view.accessibilityIdentifier = "sessionExpired.dialog"
+
+        let cardView = UIView()
+        cardView.backgroundColor = AppColor.cardBackground
+        cardView.layer.cornerRadius = AppRadius.lg
+        cardView.clipsToBounds = true
+
+        let warningImageView = UIImageView(
+            image: UIImage(systemName: "exclamationmark.circle.fill")
+        )
+        warningImageView.tintColor = UIColor(hex: 0xF05A5A)
+        warningImageView.contentMode = .scaleAspectFit
+        warningImageView.isAccessibilityElement = true
+        warningImageView.accessibilityLabel = "登录状态异常"
+
+        let titleLabel = UILabel()
+        titleLabel.text = "登录提醒"
+        titleLabel.textColor = AppColor.textPrimary
+        titleLabel.font = .systemFont(ofSize: 20, weight: .semibold)
+        titleLabel.textAlignment = .center
+
+        let messageLabel = UILabel()
+        messageLabel.text = "当前用户已在其他设备登录，\n请重新登录"
+        messageLabel.textColor = UIColor(hex: 0x4B5563)
+        messageLabel.font = .systemFont(ofSize: 14)
+        messageLabel.textAlignment = .center
+        messageLabel.numberOfLines = 0
+
+        confirmButton.accessibilityIdentifier = "sessionExpired.confirmButton"
+        confirmButton.addTarget(self, action: #selector(confirmTapped), for: .touchUpInside)
+
+        let contentStack = UIStackView(arrangedSubviews: [
+            warningImageView,
+            titleLabel,
+            messageLabel,
+            confirmButton,
+        ])
+        contentStack.axis = .vertical
+        contentStack.alignment = .fill
+        contentStack.spacing = 16
+        contentStack.setCustomSpacing(4, after: titleLabel)
+        contentStack.setCustomSpacing(20, after: messageLabel)
+
+        view.addSubview(cardView)
+        cardView.addSubview(contentStack)
+
+        cardView.snp.makeConstraints { make in
+            make.center.equalToSuperview()
+            make.leading.trailing.equalToSuperview().inset(32)
+        }
+        contentStack.snp.makeConstraints { make in
+            make.edges.equalToSuperview().inset(24)
+        }
+        warningImageView.snp.makeConstraints { make in
+            make.height.equalTo(64)
+        }
+    }
+
+    @objc private func confirmTapped() {
+        guard !didConfirm else { return }
+        didConfirm = true
+        confirmButton.isEnabled = false
+        onConfirm()
+    }
+}
diff --git a/suixinkanTests/SessionExpiredDialogViewControllerTests.swift b/suixinkanTests/SessionExpiredDialogViewControllerTests.swift
new file mode 100644
index 0000000..4e9df0a
--- /dev/null
+++ b/suixinkanTests/SessionExpiredDialogViewControllerTests.swift
@@ -0,0 +1,62 @@
+//
+//  SessionExpiredDialogViewControllerTests.swift
+//  suixinkanTests
+//
+
+import UIKit
+import XCTest
+@testable import suixinkan
+
+/// 登录失效弹窗测试，覆盖强制展示配置、Android 对齐文案与确认防重。
+@MainActor
+final class SessionExpiredDialogViewControllerTests: XCTestCase {
+
+    func testDialogUsesForcedPresentationAndAndroidCopy() throws {
+        let dialog = SessionExpiredDialogViewController(onConfirm: {})
+        dialog.loadViewIfNeeded()
+
+        XCTAssertEqual(dialog.modalPresentationStyle, .overFullScreen)
+        XCTAssertEqual(dialog.modalTransitionStyle, .crossDissolve)
+        XCTAssertTrue(dialog.isModalInPresentation)
+        XCTAssertTrue(dialog.view.accessibilityViewIsModal)
+
+        let labels = dialog.view.allSubviews(of: UILabel.self)
+        XCTAssertTrue(labels.contains { $0.text == "登录提醒" })
+        XCTAssertTrue(labels.contains { $0.text == "当前用户已在其他设备登录，\n请重新登录" })
+
+        let button = try XCTUnwrap(
+            dialog.view.allSubviews(of: UIButton.self).first {
+                $0.accessibilityIdentifier == "sessionExpired.confirmButton"
+            }
+        )
+        XCTAssertEqual(button.title(for: .normal), "确认并退出登录")
+    }
+
+    func testConfirmCallbackOnlyRunsOnce() throws {
+        var confirmationCount = 0
+        let dialog = SessionExpiredDialogViewController {
+            confirmationCount += 1
+        }
+        dialog.loadViewIfNeeded()
+        let button = try XCTUnwrap(
+            dialog.view.allSubviews(of: UIButton.self).first {
+                $0.accessibilityIdentifier == "sessionExpired.confirmButton"
+            }
+        )
+
+        button.sendActions(for: .touchUpInside)
+        button.sendActions(for: .touchUpInside)
+
+        XCTAssertEqual(confirmationCount, 1)
+        XCTAssertFalse(button.isEnabled)
+    }
+}
+
+private extension UIView {
+    func allSubviews<View: UIView>(of type: View.Type) -> [View] {
+        subviews.flatMap { subview -> [View] in
+            let current = (subview as? View).map { [$0] } ?? []
+            return current + subview.allSubviews(of: type)
+        }
+    }
+}