Abstract:This paper gave a brief introduction to strengths and shortcomings of thermal relay, electronic motor protector and intelligent motor protector, elaborated on proper selection of intelligent motor protector, compared several common operating modes of intelligent motor protector, including protected mode, terminal control mode, half-duplex communication mode and full-duplex communication mode, introduced the actual situation of the application of these four modes, and finally put forward suggestions and solutions to issues related to intelligent motor protector’s industrial application.