Multi motor synchronous control system is one of the core of vehicle driving safety.In order to improve the reliability and control accuracy of distributed electric vehicle in straight line,an improved multi motor synchronous control strategy based on torque state observer was proposed.Combined with vector control algorithm,the characteristics of the speed compensator in the bias coupling structure were analyzed to improve.According to the control requirements of synchronization error and tracking error in multi motor synchronous system,the design method of multi motor synchronous torque state observer was given.The simulation results show that the synchronization error and tracking error of the system can be reduced by 69.23% and 64.38% respectively compared with the traditional deviation coupling control.It is verified that the proposed control strategy makes each motor have higher synchronization accuracy and better robustness.The experimental results of the vehicle speed control and stability under linear condition further verify the correctness of simulation results and the stability of vehicle driving.