In order to improve the design expression level of cultural and creative products with ethnic cultural features, build an effective link from "product" to "life", and reduce the problems of low utilization of cultural knowledge in design and incoherence between product organization structure and source culture logic, the work aims to introduce an expandable innovation method to construct a cultural and creative design evaluation model. From the multidimensional semantics of Pan Yao culture, the Basic-element Model was constructed according to the way of "cultural elements + creative language". The evaluation indexes were established through factor analysis and in order to overcome the limitations of a single evaluation method in the evaluation of cultural and creative products, a Game Theory Combination Weighting Method that integrated the subjective and objective aspects to solve the comprehensive weighting of the indexes was proposed, and the design elements with higher degree of excellence were selected based on the results of the weighting. Then, combined with expandable diagram and elemental association, an effective and scientific creative design scheme was generated. The method could improve the accuracy and superiority of the use of elements in the process of product design, build a complete guidance path from design conception to transformation of elements, and provide new ideas for the ethnic cultural and creative design. The introduction of expandable theory shifts the design perspective from "things" to "matter", formalizes the design thinking process, transforms the semi-empirical and dark-box thinking status quo of design, and helps designers to choose the direction of innovative thinking and form creative design schemes.