The work aims to expand the application of Chashan Yao costume elements in modern furniture, to protect and inherit the traditional costume culture of Chashan Yao. Therefore, the product optimization design logic of RIR-MOO (relative importance level "multi-objective optimization") is integrated into the product design of furniture products, so that the design of furniture product is deeply integrated with traditional national culture. Firstly, based on the RIR-MOO logic process, the key needs of the users were screened and the correlation between user needs and design objectives was calculated to determine the design objectives of the furniture products. Secondly, the extended semiotic theory was applied to build a database of element feature maps for Chashan Yao costumes, and then the extended primitive transformation was used to transform the original element symbols into design element symbols. Finally, the design schemes for the furniture products were generated. Combined with the specified design case practice, the practicality of the design process was elaborated. Based on RIR-MOO and extended semiotics, the method of designing elements of the Chashan Yao costume has enriched the theoretical study of the traditional dress culture of the Chashan Yao people. The integration of Chashan Yao costume elements into the design of furniture products shows the compatibility between national culture and modern home environment, which focuses on the proper integration of the specific design and the human settlement environment and also provides an effective design idea and method reference for the creative design of furniture products based on the national traditional costume culture.