Customer involvement in product innovation can improve design efficiency effectively. Identifying customer knowledge quickly and applying it into the process of product design can enhance the product design capability of manufacturing enterprise. Rough set theory is used to simplify the variety of customer knowledge and identify the important customer knowledge. In order to select the customer with great contribution, a customer knowledge contribution measurement model based on Fuzzy Analytic Hierarchy Process and Shapley (FAHPS) is proposed to determine the importance weights of customer knowledge and member influence weights in group decision. An example is presented to illustrate the effectiveness of this model.