The long-distance and high-speed large-capacity belt conveyor is being use more and more in all walks of life. It can effectively save the cost of transportation, and bring about significant economic and social benefits. Due to the production characteristics of port logistics and transport, it has special requirements the start driving of belt conveyors. The soft start driving can not only save energy, but also meet the requirements of starting performance of the harbor belt conveyor, so it has been applied increasingly to port logistics enterprises.