In order to reduce the synchronous error and start-up time of multi permanent magnet synchronous motor,based on the traditional cross coupling control structure,combined with fuzzy self-adjusting filter and advanced synchronous compensator,a speed control method of multi permanent magnet synchronous motor based on improved cross coupling was proposed,that was,switching the working mode of fuzzy controller through mode selector,at the same time,the softening coefficient of each motor was automatically adjusted under different rated speed and load torque,so that each motor followed the softening speed trajectory in the starting process.The synchronous compensator was designed to achieve phase advance,so as to reduce the synchronization error and shorten the motor adjustment time.Finally,the simulation and comparison were carried out based on the PMSM speed control platform.The experimental results show that,compared with the traditional control structure,the maximum synchronization error of the improved cross coupling control structure is reduced by 55% and 25.7% respectively,and the speed adjustment time is reduced by 23% and 39% respectively,which effectively improves the synchronization performance and dynamic response ability of the system.