Symbol is a special language and an important medium for people to understand things. Semiotic theory is widely used in the design. With the continuous advancement of technology, the design and research of mobile phones are gradually focused on the user experience, and the interaction design is the most important part. The semiotic significance of mobile phone interaction interface and interaction design are explored based on Peirce's theory of symbol triangulation”and the“coding”and“decoding”in the process of symbol transmission. The optimization and design of mobile phone interaction interface and interaction mode will help to improve user experience satisfaction and enhance brand competitiveness.