The utility model relates to an anti -theft device, especially device is prevented opening by disposable transformer, be equipped with the axis on its characterized in that lock body and be the lockhole that linearity, diameter were not less than the wire rope diameter, be equipped with the briar tooth that the orientation is the same in the lockhole, wire rope's one end and lock body fixed connection, the other end is equipped with wears to draw the stick, the when used is trussed up the switch lever on valve body or power box with wire rope, then with wire rope through wear to draw the stick lockhole penetrates and in and taut wire rope locking switch lever, wire rope can only be to taut orientation removal under the effect of briar tooth, in the time will launching, check the anti -fake mark on the lock body by the staff after, with the wiring clip with wire rope cut off can, the utility model has the characteristics of the emergence that the user launched electric power suspended, running water, heat supply privately and supplied the natural gas condition is effectively stopped to only, the unable reuse's of code characteristic, also has easy operation, convenient to use, the theftproof is effectual, the practicality is strong.