The utility model discloses a stand -by power supply hauls oneself willingly into experimental auxiliary device, including the canister, inside the fixing of canister is provided with the insulation board, fixed being provided with relay unit and terminal unit on the insulation board, relay unit includes a plurality of relays, and equidistant range is in one side of insulation board, the terminal unit includes the multiunit terminal of equidistant range on the insulation board opposite side, and its group's number is the same with the number of relay, and every montage terminal is all including normally opening terminal, normal close terminal and the electric appliance wiring post that continues, the NO -contact who normally opens terminal and relay unit is connected, and the normal close terminal is connected with relay unit's normally closed contact, then electric appliance wiring post and relay unit's excitation coil contact connection. The utility model provides high stand -by power supply hauls oneself willingly into experimental efficiency and reliability, reduces artificial uncertain factor influence test result, can satisfy the experimental demand that various electric pressure stand -by power supply hauled oneself willingly into the device.