Knowledge management plays an important role in the management and control of product quality. In order to improve the efficiency of knowledge utilization in the product processing and study the knowledge flow with consideration of knowledge providers, a new method based on social network analysis is proposed in this work. Considering the social background of the different knowledge providers, the center degree of each provider could be obtained. With this value of center degree, the position of different kinds of knowledge could be calculated as well. Meanwhile, the use of correlation analysis software could help to optimize the tactic of task. Thus, on the one hand, the using and the flow efficiency of the knowledge in the product processing can be optimized more comprehensively, and on the other hand the management and control process of the product quality could be greatly improved.