The invention provides an air-cooled heat-cutting device for plastic granulation, which includes a discharge die head, a cooling fan, an air-cooled heat-cut cover body and a cutting assembly. The air-cooled heat-cut cover body is an elliptical cylinder with a wide top and a narrow bottom. , the material cutting assembly includes a motor, a cutter frame mounted on the output end of the motor, and several blades mounted on the cutter frame, and a cover is provided on one end surface of the air-cooled heat-cutting cover, and the The motor is installed on the other end surface of the air-cooled heat-cutting cover body, the cover opening is provided with a cover matched with it, the discharge die head is embedded in the cover, and the several blades are inclined to the discharge die. On the discharge surface of the material die head, the lower bottom of the air-cooled hot-cut cover is provided with an air inlet and an air outlet, and the air inlet of the air-cooled hot-cut cover is connected to the air outlet of the air cooler. Compared with the prior art, the present invention has simple structure, and saves the maintenance cost of regularly cleaning the particles stuck on the air-cooled hot-cutting cover body.