Abstract: In the production process of a multi motor drive system of belt conveyor, if individual motor speeds are not synchronized, it can cause conveyor belt breakage and mechanical and electrical equipment damage. Therefore, it is necessary to carry out speed collaborative control on the multi motor drive system of belt conveyors. The traditional deviation coupling control method has good comprehensive performance. But it has problems such as complex control structure, poor scalability, and susceptibility to load disturbances during startup and steady-state operation, resulting in speed deviation. In order to solve the above problems, a speed synchronization control method for multi motor drive system of belt conveyor is proposed. By introducing virtual motors, and adopting indirect coupling relationships between each motor and virtual motors instead of direct coupling relationships between motors in traditional deviation coupling structures, the synchronous compensator model of the system is simplified. The synchronous error between each motor is reduced, and the synchronous control of each motor is achieved. When the number of motors changes, only new speed variables need to be added to the virtual motor speed synchronous compensator. The speed synchronous compensator of the original system does not need to be changed, enhancing the system's scalability performance. The analysis results show the following points. ① During the system startup stage, the improved deviation coupling structure has good synchronization performance between the rigid and flexible connected motors. Compared with traditional deviation coupling structures, the synchronization error between rigidly connected motors is reduced by 4.0 r/min, providing good initial power for the main drive drum during start-up. ② When the load suddenly changes, the synchronization error between rigid connected motors is 1.7 r/min. The average synchronization error between the rigid and flexible connected motors is 14.6 r/min, which is 5.2, 31.7 r/min lower than the traditional coupling deviation structure, respectively. This can effectively reduce the damage to the mechanical structure of the motor caused by the load sudden change.