The utility model discloses a relay testing device and a system. The device comprises a detection processing unit, a program-controlled direct-current power supply, a program-controlled alternating-current power supply, an analog load, a contact feedback device, a resistance measuring device and a relay connecting end. The detection processing unit is connected with the program-controlled direct-current power supply, the program-controlled alternating-current power supply, the analog load, the contact feedback device and the resistance measuring device, and the program-controlled direct-current power supply, the program-controlled alternating-current power supply, a power supply polarity switching device, the analog load, the contact feedback device and the resistance measuring device are connected with the relay connecting end; and the detection processing unit is used for controlling direct-current power provided by the program-controlled direct-current power supply for a relay to be tested, alternating-current power provided by the program-controlled alternating-current power supply for the relay to be tested and over current provided by the analog load for the relay to be tested according to received external control commands, the contact feedback device is used for returning contact feedback signals to the detection processing unit, and the detection processing unit is used for generating testing results and reading measurement results generated by the resistance measuring device.