The present disclosure relates to a method for protecting an application program in a terminal device, and a terminal device thereof. The method includes: intercepting a request for starting an application program; determining whether the application program needs protection; and starting a protection interface before starting the application program, if the application needs protection. According to the present disclosure, the protection interface is launched before starting the application program when the terminal device detects that the application program needs protection, thereby protecting the application program comprehensively and thoroughly.