Abstract: For a permanent magnet synchronous motor (PMSM) control system with unknown motor parameters, it is important to identify the motor parameters to improve its control performance. This research uses Popov's hyper-stability theory to design the adaptive law of identifying system. The approach of coordinate rotation was used to compensate the input voltage drop caused by dead time characteristic of inverter. Values of stator resistance and dq-axis inductance were obtained by identification. Based on the identification results, the motor model was constructed and its controller parameters could be designed by engineering design methods. Experimental results show that the accuracy of identification could be improved with the dead time compensation and the motor model based design method of controller parameters could reduce the time of parameters debugging. As a result, the dynamic performance of the motor control system is good.