In recent years, with the development of intelligent terminals and mobile internet, the research for mobile learning platform or software based on 4A(Anyone, Anytime, Anywhere, Anydevice) is constantly innovated and applied, and intelligent terminal is continuously improved in promoting its educational function and is continuously innovated in meeting people's active learning needs. Through the analysis of the main characteristics of the mixed teaching mode based on the public platform of WeChat and the current situation of higher education in China, taking the civil engineering course of design principle of steel structure as an example, the teaching reform methods of civil engineering courses based on the combination of WeChat public platform and traditional teaching were discussed, and a preliminary design of the mixed teaching mode was put forward.