Marine propellers are an important component of the ship"s power system, and their assembly quality directly affects the output efficiency of the ship"s power system. At present, domestic shipyards can choose suitable fitting techniques based on their own ship type and hardware conditions. However, if they want to further improve the efficiency and quality of propeller shaft fitting on the current basis, traditional fitting methods still have significant limitations. Therefore, this article proposes a reverse modeling based propeller shaft fitting process concept, which improves the convenience and quality of propeller shaft fitting through digital means such as 3D scanning and virtual simulation. It effectively eliminates the tedious process of multiple oiling, fitting, disassembly, and processing required for the traditional physical stern shaft and physical propeller fitting. At the same time, it also eliminates the situation of relying on worker experience to judge the grinding position and processing quantity in the traditional fitting process. This not only significantly reduces labor and material consumption, shortens the fitting cycle of the propeller shaft, but also effectively improves the accuracy and quality of propeller shaft fitting.