Modal theory is an important basis for studying cultural inheritance and dissemination. This paper combines modal theory and AIGC technology to innovate the cultural and creative design method. Through the calculation and analysis of modal recognition degree and other indicators, the modal factors that should be applied or innovated in cultural and creative design are identified. Using this paper’s cultural and creative design method, the analysis of Liangzhu culture and Shu brocade patterns is conducted separately. In the Liangzhu culture modal recognition, the higher recognition is pattern representation, morphological representation, and artifact function, and the lower recognition is color representation, aesthetic concept, material representation, and philosophical thought. The order of the popularity of the modal elements of pattern representations is from high to low: abstract pattern > animal pattern > geometric pattern. The traditional patterns of Shu brocade are in the order of color expression: A (0.209) > subject matter content, D (0.206) > surface features, C (0.162) > organization, B (0.148) > aesthetic meaning, F (0.138) > symbolic meaning E (0.137). When using AIGC to assist cultural and creative design, it is necessary to take into account the modal factors with smaller weight values to ensure that the final design can be loved by the public and achieve the dual goals of cultural heritage and economic benefits.