Disclosed is a connector for preventing unlocking which includes a signal pin transferring a signal; a body into which the signal pin is inserted and which is electrically isolated from the signal pin; a first housing having a hollow portion into which one end of the body is inserted, a thread groove and at least one protruding portion or a plurality of fixing grooves formed at an inner circumferential surface of the other end thereof; and a second housing having a hollow portion into which the other body end is inserted and through which the second housing is moved along an outer circumferential surface of the body in an axial direction.