Abstract: In view of problems of great investment at early stage and complex structure of CST soft start device of belt conveyor, the paper proposed a design scheme of controllable speeder of belt conveyor. It briefly introduced composition and working principle of the device and gave implementation of soft start function and control strategy of power balance with multi-motor driving, and detailedly introduced hardware and software design of electrical control system of the device. The result of experiment test showed that the device has good performance and high performance-price ratio, which is ideal driving device for belt conveyor with large-capacity and long-distance.