This article is aiming at complex test characteristics and working process of the circuit, make full use of the hardware and software of the computer and test equipment capability, using GPIB interface technology for device interconnection, implements a set of power supply automatic on electric power system. The computer can control many powers to realize circuit's poweron and off .Also the time interval of power can control by compute. Rely on the computer control of the equipment, reduce the complexity of the tester operation, improve efficiency, and effectively avoid the wrong operation to achieve the results of automatic measurement.This method has been used in several projects, and the results show that this method is more efficiency and reliability.