Abstract: For problems of motor overload and even damaged caused by power unbalance which easily appears in processes of load changing, acceleration and deceleration of multi-motor drive for belt conveyor, a torque distribution formula of motor was deduced according to torque distribution principle. Master-slave control method of frequency-conversion drive was adopted, namely vector control with closed loop of speed and magnetic chain was used for the master motor and speed cascade torque control was used for the slave motor, so torque closed-loop control was done under the case that torque distribution of the master and slave motor were given. Model of power balance control system was established and the structure of dual-motor drive power balance control system was given. The result of Matlab simulation shows that output torques of the motors can achieve proportional distribution in processes of load changing, acceleration and deceleration, which proves effectiveness of the power balance control system.