The invention discloses an anti-pulling device for a lock. The anti-pulling device comprises a lock shell, a key hole connecting piece is arranged in the lock shell, a sliding hole is formed in one end of the key hole connecting piece, a first transmission rod in sliding connection with the sliding hole is inserted into the sliding hole, the first transmission rod is sleeved with a limiting ring fixedly connected with the first transmission rod, the limiting ring is located on one side of the key hole connecting piece, a groove is formed in the lower side of the lock shell, a spring bolt in sliding connection with the groove is inserted into the groove, one end of the first transmission rod penetrates the groove in the lock shell and is fixedly connected with one end of the spring bolt. The anti-pulling device has the beneficial effects that a traditional anti-pulling device for the lock is improved, a power source is controlled to be started or stopped through contact between the keyand the spring bolt and a lock groove, the transmission device is controlled to move, motion of the anti-pulling device is controlled further, the complex degree of the traditional anti-pulling devicefor the lock is reduced, meanwhile, modern science and technology are increased, the lock reliability is greatly improved, and the needs of modern life are better met.