The utility model provides a brake shoe protective device. A trigger electrode I is in contact with a drum brake disc, brake shoes are arranged outside the brake disc, a movable brake shoe seat is arranged outside the brake shoes, a fixed brake seat is arranged outside the movable brake shoe seat, a trigger electrode II is in contact with the movable brake shoe seat, and the trigger electrode I and the trigger electrode II are connected with a console through signal wires. The protective device has the characteristics of simple structure and scientific design, and can detect the abrasion condition of the brake shoes, completely monitor the brake shoe clearance after a brake is loosened and effectively reduce slippage accidents.