Interface device, test system and method applied to distribution automation test

The invention provides an interface device, a testing system and a testing method applied to distribution automation testing. Comprising a plurality of aviation sockets used for being connected with a tested device, and the tested device is a power distribution automation terminal or a relay protection device; the plurality of banana sockets are used for being connected with a tester, the tester is used for testing tested equipment, the aviation socket and the banana sockets are connected through connecting wires, and the connecting wires are arranged in the interface device; the power socket is used for being connected with an external input power supply, the power switch is further connected with at least part of the aviation socket, and connecting lines between the power switch and the power socket and between the power switch and the aviation socket are standard power lines. As the aviation socket and the banana socket are internally connected, the banana socket and the tester are connected through the ba