Dear Baiguang Liu,
You recently made a request to reset your password or unlock your Apple Account. Please click the link below to continue.
Reset Password or Unlock Apple Account
If you did not make this change or you believe an unauthorised person has accessed your account, you should go to iforgot.apple.com to reset your password immediately. Then sign into your Apple Account account page at https://account.apple.com to review and update your security settings.
Sincerely,
Apple Support