The invention relates to an air-air cooling three-phase asynchronous motor fan cover, comprising a connecting frame which is provided with an air inlet; the connecting frame is respectively provided with an upper junction plate, a middle junction plate and a lower junction plate, wherein the other ends of the upper junction plate, the middle junction plate and the lower junction plate is respectively provided with a first wind screen, a second wind screen and a third wind screen; the end of the first wind screen and the end of the wind screen are provided with bottom-end junction plates, and the lower part of the first wind screen is provided with an air outlet which is communicated with the air inlet. The first wind screen, the third wind screen, the bottom-end junction plate and the connecting frame in the invention form a fan cover structure. Compared with the existing fan cover, the air-air cooling three-phase asynchronous motor fan cover can reduce the working procedure of immovable fitting, avoids windage resistance caused by that cooling air flow generated by an outer fan suddenly turns; the upper junction plate and the first wind screen, the middle junction plate and the second wind screen and the lower junction plate and the third wind screen all adopt circular arc transition, thus bringing smoother air flow path flowing, enlarging a wind collection chamber and improving heat dissipation effect.