Abstract: The agricultural intelligent motor protection system not only has the protection function, but also the measurement and control function, which can measure the three-phase full power of the circuit. Based on the current situation of system operation, this paper studies the overall structure, module, software and function of PLC in agricultural intelligent motor protection system.The system is mainly composed of three parts: main module, display module and main expansion module, which can complete the control of motor bidirectional start and direct start. The results of FMEA risk detection and logic application test show that the designed system is reliable.