The work aims to solve such problems as large wear and low control accuracy of the mechanical structure existing during the multi-motor synchronous control of the traditional mechanical connection. Based on the structure of relative coupling control system, and combined with the fast nonsingular terminal sliding-mode control, a kind of synchronous control strategy for the multi-motor synchronous speed was proposed. The algorithm could rapidly respond to the motor under different speeds and disturbance loads, which reduced the influence of disturbance on the system and further improved the synchronization accuracy during the operation of multiple motors. The proposed control algorithm has better control performance and can meet the needs of the actual production.