Trademark extension refers to the use of existing trademarks by companies to enter new business areas or launch new products. The purpose is to take advantage of consumers' good attitudes and perceptions of existing trademarks and their love for houses and blackbirds, thereby reducing the risk of adopting new products. Trademark risks and savings on marketing expenses. Different trademarks have different extendibility. Therefore, the added value that trademark extension brings to enterprises is also different. To analyze the value of a trademark from the perspective of trademark extension, the following factors must be comprehensively considered: 1. The popularity of the trademark and customers' attitude towards the existing trademark; 2. The adaptability of the existing trademarked products and the extended products; 3. The consistency of the trademark image before and after the extension Sex etc.