In order to accurately determine the fault process of double-Y-type asymmetric three-phase asynchronous motor, based on the theory of motor asymmetry, with the help of ANSYS finite element analysis software, the simulation model of double-Y-type three-phase asynchronous motor is built, the abnormity of three-phase current under stator winding asymmetry is verified, and the effect of resistance asymmetric rate on the working characteristic of the motor is analyzed. Three operating conditions of motor failure are discussed. The results show that the three-phase current abnormity caused by the winding asymmetry amplifies cyclically, and the degrees of asymmetry of amplitude and phase angle of three-phase current increase with the increase of the fault degree.