Abstract: The generalized module, one of the basic elements of parametric product platform, can effectively support product variant design and design for mass customization. A similarity analysis method is proposed to solve the similarity measure and variation law of function and process of the non-isomorphism generalized module, which can mine the hidden design knowledge and process resources. The structure, function and process information of the product modules are converted into eigenvector by range identification. The parameters of different scales in non-isomorphism classes are normalized to eliminate the effect of different dimensions. Then, the similarity measure of function and process information is completed by vector matching, and the results are stored in a similarity storage table. The feasibility and effectiveness of the proposed method are verified by a case study of high and middle pressure valve.