The utility model discloses a double -phase low -voltage protect relay function test system, the system include rack, front -end processor, test signal source, acquisition control device, adaptive device and switching power supply, and double -phase low -voltage protect relay is connected with the adaptive device, and switching power supply is to the power supply of double -phase low -voltage protect relay, wherein: the front -end processor is used for receiving test case to with the analytic control command that is of test case, test signal source is used for receiving control command to send test signal to the acquisition control device, the acquisition control device is used for receiving control command, and carries out functional test to double -phase low -voltage protect relay. The utility model discloses a double -phase low -voltage protect relay function test system adopts on - line monitoring method automatic, intelligent, that integrate, can test double -phase low -voltage protect relay's function on accurate high -efficient ground to the drawback of double -phase low -voltage protect relay existence can be in time discover, nuclear power station circuit fault risk can be effectively reduced.