Abstract: Product quality is the source of enterprise benefits,for the spiral bevel gear,firstly,the production process of the spiral bevel gear was analyzed;Then,by applying Statistical Process Control (SPC) theory and method,the key points of quality improvement was determined and the process capability of the control points were analyzed and the quality improvement measures and plan were formulated.Finally,the regression analysis and the full factorial experimental design are conducted to find the optimal combination of the key factors and the influence of various factors,such as carburizing temperature,carburizing holding time,quenching temperature,tempering temperature and carburizing holding time.Through the implementation of the success of this project,the failure rate of the spiral bevel gears was reduced,and customer satisfaction was improved,the significant is effect.

Key words: Statistical Process Control (SPC), quality improvement, experimental design, the spiral bevel gear