The invention relates to a cooling system of a forced air cooling platypelloid type three-phase linear asynchronous motor, adopting the mode of three-chamber and four-passage ventilation. An iron core in the cooling system is formed by a plurality of dovetail groove-shaped lamination provided with circular tops and bottoms, wherein both sides of the iron core are provided with clamp plates which are tightly clamped by threaded bolts, front end plates and rear end plates are respectively welded at both ends of each clamp plate, and the upper part of each clamp plate is connected with an upper cover plate so as to form a cold air intake and outtake box body used as an plenum chamber; at least a blower is installed on the upper part of the plenum chamber and is fixed on the upper cover plate, a pressure device is installed in the plenum chamber which is arranged above a radiating fin and is adjacent to a ventilation opening, and cold air in the plenum chamber passes through the ventilation opening and flows into an end air chamber; and a deflector is installed at the upper side of the ventilation opening in the end air chamber and is in the shape of bat, winding overhang is arranged in the end air chamber, and wind screens are respectively installed on the lateral surface and the bottom surface of the end air chamber. The forced air cooling motor has the advantages of high efficiency, small volume, light weight and little space occupation, thereby reducing the weight of a car body and enhancing the bearing capacity of the car.