The utility model aims to solve the problem that material bar water is easy to be out of limits when air humidity is larger or water content of material bar is higher, disclosing a novel air blowing device of an extrusion machine. The device comprises a driving motor, a fan, a fan air outlet pipe, an air inlet, an air outlet, an electric heater and a temperature detector connected on the inner side of the fan air outlet pipe, wherein the electric heater is connected with the temperature detector in series. Air flow which enters the air blowing device of the extrusion machine of the utility model is exhausted after heated by the heater, thereby effectively removing water of material bar, increasing production efficiency, and solving the problem that the air humidity and water content of material bar affect the quality of sequent products.