Abstract: The manufacturing quality of reactor pressure vessel (RPV) directly determines its reliability, safety and service life. Now, the research on the quantitative evaluation of the RPV inherent quality is still blank. Taking RPV as the research object, a set of applicable quality evaluation model is established, the weight of each evaluation item has been set up by analytic hierarchy process and analyzed quantitatively. It is found that metal material, welding and surfacing directly determine the inherent quality of RPV, and the weight sum of nozzle barrel, nozzle, core barrel, wedding between nozzle and barrel is more than 25 percent, which are the key in RPV manufacturing process. The result provides a comprehensive judgment basis for improving the manufacturing quality and reliability of RPV and planning more targeted supervision plans, and also provides a reference for the quality evaluation of similar mechanical equipment.