For existing status of multi functions and complex structure of electrical control system of mining equipment, a function test system of electrical control box was developed. The system tests output response of electrical control box through simulating control commands and working status signals, and has testing functions of action control, fault diagnosis performance, protection performance, action performance and so on. Moreover, compared with handheld testing equipments, the system can realize monitoring function of multi-signal composition input and output signal, and simulate more control results caused by incorrect operation in application . The test result showed validity of the system.