Abstract: The principle of fault detecting for scraper conveyor’s chain was described,and a design scheme of on-line monitoring system of fault of scraper conveyor’s chain was also proposed.The composition of the online monitoring system was given and the design of secondary instrument and development of control software of ground were introduced in details.The on-line monitoring system can real-timely monitor faults of scroper conveyor’s chain such as chain broken,scraper broken, rotor locked,chain jumping,and transmit the monitored information to monitor station,so as to ensure the safety of production.