The invention discloses a hot air anti-icing method for an engine inlet rotary rectification cover. The hot air anti-icing method for the engine inlet rotary rectification cover comprises the steps that 1, hot air is divided into two parts, one part of hot air flows out through a labyrinth seal and a booster stage rotor outlet, the other part of hot air enters an air collecting cavity through an air leading pipe, and the hot air entering the air collecting cavity is called anti-icing hot air; 2, the air collecting cavity is connected with the cover and a fan, thus the air collecting cavity, the cover and the fan rotate together, and the anti-icing hot air in the air collecting cavity can enter the cover; and 3, an included angle is formed between the inner wall and the outer wall of the cover, thus a hot air channel forms a gradual contracting channel from front to back, and the anti-icing hot air flows out through air outlets in the root of fan blades and enters an engine main channel. Through the hot air anti-icing method, the problem of low efficiency of the prior art is mainly solved. An air compressor leads the hot air to conduct heating protection on the whole cover in a forced-convection heat exchange mode, the surface temperature of the cover is increased, and the problem is solved.