The invention relates to an interlocking device capable of effectively preventing misoperation of a double-open type rear door of switch equipment. The mechanism is divided into three modules, namely, a vertical translation module, a joint module, a horizontal translation module, wherein the horizontal translation module is arranged on the rear door, the vertical translation module is arranged on a bending edge of a side plate and is directly matched with a grounding switch, and the joint module is a transition module and is used for transferring motion and reducing friction like a joint. The interlocking device acts with the action of the grounding switch during switch-on operation, a horizontal sliding rod is finally withdrawn from an opening hole of a fixed beam, and the rear door can be opened; with the action of the grounding switch during switch-off operation, the horizontal sliding rod of the interlocking device finally enters the opening hole of the fixed beam, and the rear door cannot be opened. By the device, interlocking of the grounding switch and the double-open type rear door can be achieved, the double-open type rear door cannot be opened when the grounding switch is switched off and can be opened when the grounding switch is switched on, a live-line gap is prevented from being entered, the requirement of five-proof interlocking is met, and an electric shock accident is prevented.