The utility model relates to the technical field of cooling and noise reduction of high-voltage variable-frequency motors. The low-noise cooling fan for the high-voltage variable frequency motor comprises a fan body, the fan comprises a fan motor, a fan, a junction box and a noise reduction cover, the noise reduction cover comprises a cylindrical cover body with openings in the two ends. the rightend of the cylindrical cover body is detachably connected with a right end cover; the fan is coaxially connected with an output shaft of the fan motor and located in the noise reduction cover, one end of the noise reduction cover is detachably connected with a shell of the variable frequency motor, air inlet meshes are evenly distributed in the other end of the noise reduction cover in the circumferential direction of the noise reduction cover, and a junction box of the fan motor extends out of the noise reduction cover and is installed outside the noise reduction cover. Under the condition that the total length is not changed, noise generated by equipment can be effectively reduced, the cooling effect on the variable frequency motor is enhanced while noise pollution is avoided, and heatgenerated in the running process of the fan motor can be cooled.