Abstract: According to nonlinear, stochastic and time-varying characteristics of chain tension control of scraper conveyor in coal mine underground, a chain tension control system of scraper conveyor was proposed which was based on sliding mode control method to improve dynamic performances of tension control system. The method adopts exponential reaching law to make the tension control system run along prescriptive state trajectory in a certain characteristic. The simulation results show that tension control system based on the method has good dynamic characteristics, strong robustness and superior interference immunity.