The invention discloses a method for compressed air energy storage through a coal mine downhole roadway. The method comprises the steps that firstly, a roadway section is transformed, specifically, arock mass of roadway surrounding rock is subjected to high-pressure grouting for reinforcement, and a large-range stable force bearing layer is formed; a circular reinforced concrete lining is constructed according to the shape of the roadway section, and after the inner surface of the lining is smoothed, a rubber or steel lining layer is pasted to the inner surface of the lining; the space between the original section of the roadway and the reinforced concrete lining is subjected to grouting filling; then the two end faces of the roadway are plugged; and finally, a flexible air storage bag isput in the treated roadway. In the working process, compressed air is stored and called through an air inlet pipe and an air outlet pipe which are connected to the flexible air storage bag. Accordingto the method, a reliable, safe and easy-to-maintain coal mine downhole roadway compressed air energy storage path is provided.