The invention provides a mini brake device. The brake device is composed of a brake spring (4) and magnetic drive units (5a, 5b). The brake spring presses a brake disc (2) on a braked object to brake, the magnetic drive units overcome the racking force of the brake spring to relieve brake. The brake device is characterized in that the magnetic drive units are composed of first yokes (8a, 8b), second yokes (9a, 9b), magnet windings (7a, 7b) and permanent magnets (6a, 6b), at least one magnet winding and a permanent magnet are arranged in the first yoke and the second yoke, one of the first yoke and the second yoke is set as a fixing body, the other one is a movable body, the aspiration directions of the attraction force of the magnet winding and the permanent magnet are set same with the attracted direction of the movable body, moreover, a current energizing circuit (12) is used for relieving and applying brake through power up and down of the magnet windings.