Intangible cultural heritage faces several challenges, including a fragile transmission system, disconnection from modern life, and poor market adaptability. This study takes the Jingsha tenon-and-mortise woodcarving, an important example of Chinese intangible cultural heritage, as a case study to address the issue of the disconnection between traditional craftsmanship and contemporary demands. Methods: A sustainable development model based on user–AIGC–craftsman collaboration is proposed. The research integrates Kano Model and Analytic Hierarchy Process (AHP) based demand analysis, AIGC-generated design solutions, Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) evaluation, and Cursor and MCP 3D modeling technologies. The results indicate that this approach reduces design confirmation time from three days to one, minimizes material waste through precise size specifications, and achieves high user satisfaction. The study demonstrates that combining user-centered design with AI-assisted craftsmanship creates a balanced pathway for the sustainability of intangible cultural heritage, while addressing issues of cultural preservation, economic feasibility, and resource efficiency. This tripartite model offers a replicable framework for the sustainable development of traditional crafts globally.