The invention discloses an air guiding device for an air cooling tower of an indirect air cooling unit. The device is composed of a plurality of guiding plates. The guiding plates are arranged outside the air cooling tower in a surrounding manner and are as high as an air cooling radiator. Certain angles A are formed by the guiding plate set and the tangent line of the outer edge of the radiator at the bottom of the air cooling tower, and the angles change along with changes of the environmental wind direction. When environmental wind blows, the device adjusts the angles A according to the environmental wind direction, ambient air is guided, and therefore a vortex is formed, cooling air is evenly distributed on all sectors of the radiator, and convection between the cooling air and finned tubes is enhanced. Besides, the strength of transverse cross through flow is weakened through the vortex to a certain degree. According to the air guiding device, the influence of the environmental wind on the thermal performance of the air cooling tower is weakened as a whole, and the economical efficiency and safety of the indirect air cooling unit are improved.