The work aims to optimize the complicated semantics during the design process of bronze device decoration, which causes the designed pattern to be separated from the essence of cultural connotation and the problem of single-patterned shape design. The most representative bronze ornaments were selected. Their characteristics were summarized and analyzed. The towering theory was adopted to obtain the feature words of the maximum design range of the design range. A graphic analysis was conducted, and the best illustration was selected as a design reference. The design was innovated based on the shape grammar, and finally a comprehensive evaluation was conducted on the design plan. As a result, the patterns derived from the tendency and shape grammar had both aesthetics and could reflect the cultural semantics behind it. The design scheme of the bronze decoration created was high satisfactory in the evaluation. The combination of extension semantics and shape grammar can effectively enhance the extraction efficiency and utilization value of bronze decoration, and provide design method and support for the innovative design of bronze decoration.