The utility model relates to a cubical switchboard isolation barrier protective apparatus, in particular to cubical switchboard isolation barrier prevents mistake and opens blocking device, its technical scheme is: including the cabinet body, be equipped with two isolation barrier on the cabinet body, two isolation barrier on be equipped with first stationary blade and second stationary blade respectively, first stationary blade and second stationary blade connect through two lock banking stops, first stationary blade and second stationary blade constitute L shape structure by dual board, be equipped with first through -hole and second through -hole on first stationary blade and the second stationary blade respectively, the lock banking stop be the rectangle structure, be equipped with three through -hole on the lock banking stop, two through -holes are the mounting hole on the lock banking stop, one of them through -hole is the lockhole, connects the lock banking stop respectively on the first stationary blade with on the second stationary blade, two lock banking stops pass through the lockhole to be connected, the lockhole passes through the electromagnetic lock locking, beneficial effect: stationary blade and lock banking stop simple structure, low cost, simple to operate.