Abstract: For problem of frequent faults of scraper and chain breakage caused by traditional artificial tension mode for chain of scraper conveyor, the paper introduced composition, working principle and operation mode of a dynamic tension control system for chain of scraper conveyor. The system controls expansion and contraction quantity of tension cylinder according to tension of chain measured by load detector, so as to realize automatic control function of tension change of chain with loads. The application showed that the system decreases attrition of chain wheel and chain and fault ratio of scraper and chain breakage, and lengthens working life of scraper conveyor.