To improve the quality of classroom teaching and understand the effectiveness of teaching in a timely manner, the multimedia teaching quality evaluation system of colleges and universities was established. Combined with genetic algorithm, through the investigation, the evaluation process of multimedia teaching in colleges and the status quo of multimedia teaching were analyzed. Many teachers were interviewed. A set of evaluation indicators suitable for college multimedia teaching quality was discussed, and the indicators were visually displayed with data. From the aspects of multimedia courseware, multimedia classroom teaching process and multimedia teaching effect, teachers' basic information, students' basic information and evaluation relationship management are analyzed. The teaching quality evaluation system of college multimedia was designed and the results were tested. The research results showed that the evaluation of teaching quality was realized through the teaching evaluation system. Therefore, the system is of great significance to improve the effectiveness of classroom teaching.