Method and system for triggering synchronous failure of authentication process

The invention discloses a synchronous failed method of triggering authentication process, which comprises: an indexed (IND) value to be sent down is calculated according to serial number (SQN) obtained by twice triggering authentication flow; the serial-number SEQ value corresponding to the IND in a universal subscriber identification module (USIM) file in a mobile station can be modified according to the calculated IND value; and the authentication flow synchronous failure can be obtained in the third triggering authentication flow. The invention also discloses a synchronous failed system oftriggering authentication process. Adopting the method and the system can realize a test that the triggering authentication flow is failed due to synchronous failure.