The invention relates to an equivalent device for a general satellite power-distribution system, which comprises a control computer, a PLC module, a signal conditioning module, a communication card and a peripheral interface cable. The communication card is arranged inside the control computer and connected to a communication port of the PLC module through a bus; the control computer transmits equivalent configuration commands of different satellite power supplies and a power distribution subsystem to the PLC module through a bus, and the PLC module is used for stimulating interfaces and functions of the satellite power supplies and the power distribution subsystem according to the received configuration commands; and the signal conditioning module performs level transformation to an output signal of the PLC module and then transmits to the a ground power-distribution test device through the peripheral interface cable, and meanwhile, a state control input signal transmitted from the ground power-distribution test device is transmitted to the PLC module after the level transformation so as to finish the inspection to the ground power-distribution test device. The invention realizesthe versatility of the equivalent device for the satellite power-distribution system, is convenient for establishing a satellite integrated test system, and also reduces the lead time of the satellite test device.