Abstract: In view of problems of single function, low reliability and poor integration and expansibility of system in existing protection system of belt conveyor of coal mine, and comparing common fault types of belt conveyor, the paper proposed an intelligent protection system of belt conveyor based on PLC and introduced hardware structure and software design of the system. The system can be operated singly and locked with several levels, has perfect interfaces of communication networking with strong expansibility, supports transmission through industrial Ethernet and has intelligent integrated control function. The actual application verified validity and reliability of the system.