The embodiment of the utility model discloses the voltage signal extraction element, it includes: shell (10) and encapsulation are in in shell (10) no. 3 group circuit branch road, wherein, every set of circuits branch road is including single phase transformer (12), the signal connection head (13) and voltage attenuator (14) of order connection, the three -phase voltage signal that can overhaul the power with the three -phase through step down with the decay after carry to the oscillograph and show respectively. And simultaneously, the embodiment of the utility model provides an it puts the test system still to disclose the electrified office of a cubical switchboard. Implement the embodiment of the utility model provides a, it examines and plays a game and put the efficiency and the precision of source phase place characteristic location can improvement office to put the signal to improve work efficiency.