Special misoperation prevention device of secondary protection system of transformer substation relates to equipment protective technical field, lacks safeguard procedures in order to solve current transformer substation's secondary protection, arranges during the operation that safeguard procedures waste time and energy and the measure is unreliable, and secondary protection system's in service problem is touched to easy mistake. The protection is equipped with the warning printed words on the mainboard, and concave type frame has three limits, and every limit is equipped with and protects mainboard matched with concave groove, but the plug of protection mainboard in the concave groove of concave type frame, switch and bee calling organ are located concave type frame outer wall, it is inboard that LED lamp and micro -gap switch all are located concave type frame, when protecting the mainboard and insert in concave type frame, presses micro -gap switch normally open contact, makes its closure, the LED lamp shines, when the protection mainboard was removed by the mistake, normally closed contact NC was closed, and bee calling organ carries out audio alert. The utility model is suitable for an equipment protective.