A pure electric vehicle loading three-phase AC asynchronous motor is taken as the research object，firstly a drive transmission system test bench of three-phase AC asynchronous motor is built to investigate the plugging turn characteristics in speed control mode of three-phase AC asynchronous motor，and the torque response rules of different motor speed errors is achieved. Further，a ramp recognition model and the calculation model of controlled variable are established，herein，a ramp adaptive launch control strategy of pure electric vehicle is presented，the simulation model through Matlab/Simulink is built，and the simulation results show that the launch control strategy can well adapt to different ramp starts.