The utility model provides a high -load controllable track brake, by the retarder casing, sliding oil cylinder and solenoid valve are constituteed, the solenoid valve is installed in retarder's casing back, be equipped with a lockpin hole on the casing back, the lockpin is controlled by the solenoid valve in lockpin hole, the sliding oil cylinder body is equipped with a ring channel, when solenoid valve powered off, the lockpin contracts in lockpin hole, the last ring channel of sliding oil cylinder is located lockpin hole's top, when solenoid valve powered on, the electromagnetic valve drive lockpin is used in sliding oil cylinder body surface face, pushed down by the wheel as sliding oil cylinder, when ring channel on the sliding oil cylinder body is relative with the lockpin hole position, the lockpin inserts in sliding oil cylinder's the ring channel, after the wheel, electromagnetic force continuous effect is in the lockpin, sliding oil cylinder is by the position of locking in the ring channel, retarder did not play braking action to follow -up wheel this moment. When solenoid valve powered off, the lockpin is retract in lockpin hole, makes progress to initial position under the effect of sliding oil cylinder body oil gas pressure in sliding oil cylinder, and retarder can continue follow -up vehicle work done.