The utility model relates to a transformer neutral point direct current detection device, including the casing, the casing is divided into the back casing and the procapsid of looks block, and back casing front end is equipped with the recess, and the block has ground connection row in the recess, and the mutual -inductor of fixing on the casing of back is cup jointed at the middle part that ground connection was arranged, and the side -mounting of back casing has the controller, and two spools are installed to the bottom, is equipped with ampere meter, microprocessor in the controller, radio signal sends and the receiver, and microprocessor sends with ampere meter and radio signal respectively and is connected with the receiver is electric, and the ampere meter is connected with the mutual -inductor is electric. The beneficial effects of the utility model are that: can gather transformer neutral point direct current and send through radio signal and send the data of gathering with the receiver, adopt open -close type current sensor, easy to assemble and maintenance need not to break off ground connection row during the maintenance, do not have the influence to the security of system, also can conveniently demolish the change bit mounted position, from area heating device, satisfy cryogenic application.