The utility model relates to a blocking device of an electrical equipment box. The blocking deice mainly comprises a magnetic coded lock, a shifting sheet and a pin rod. The blocking device is characterized in that a right-angle-shaped spring bolt is arranged at the lower part of a lock cylinder of the magnetic coded lock arranged in a lock box, a clamping pin is arranged on the inner wall of a lock box, and extends into a slot formed in the peripheral direction of the outer wall of the lock cylinder, the shifting sheet connected with the pin rod is arranged at the end part of a rotating shaft, and the other end of the rotating shaft is hinged with the end part of a handle. The blocking device is capable of preventing a key from being broken due to fatigue when the key is screwed effortlessly for a long time, and is simple in structure and convenient to use and operate.