A system for testing DC power supply performance includes a control circuit electrically connected to the DC power supply, a test device, and a control device electrically connected to the test device. The control circuit includes a micro controller capable of outputting control signals, a switch control module, and a switch module. The switch control module receives the control signals and powers up according to the control signals. The switch module is electrically connected to the DC power supply input and output terminals respectively, under control of the switch control module. The test device is electrically connected to the switch module and is electrically connected with the DC power supply input and output terminals according to the control signals. The test device reads voltages at the DC power supply input and output terminals which are transmitted to the control device.