As the key part of the hoist in coal mine, the main shaft with possible failures as structural deformation, serious wear, structural fracture and other failures in the use process, which had an important impact on the normal operation of the hoist. Xinzhi Mine was taken as an example, the structure and performance of the mine hoisting winch spindle were researched in this mine, and its structure was optimized and analyzed. Practice showed that the improved main shaft was more uniformly stressed, the phenomenon of stress concentration was significantly reduced, and it had better structural performance, which improved the work efficiency of the winch and ensured the work safety of the winch.