air inlet and the impeller wheel cover lines, and using the impeller inlet air flow evenly as the optimization criterion of tuyere optimization design was carried out.2. Combined with the original optimization design methods such as fan impeller and volute, and integrated optimization design program of impeller, volute and air inlet, the aerodynamic sketch curve is obtained.3. Practice has proved that it can guarantee not only wind pressure and air volume, but also higher efficiency, lower spec