Multimedia has great positive influence on Chinese teaching in senior high schools, such as stimulating students' interest in learning; Breaking through the difficulties in teaching content; Improving the efficiency of learning; It can also expand extracurricular knowledge points and broaden students' horizons. However, excessive reliance on and abuse of multimedia will cause teachers to prepare lessons carelessly. Less classroom communication between teachers and students; The low level of courseware making by teachers affects the teaching effect. There are too many contents in the class and it is easy to lose the focus of teaching. This paper will analyze the positive and negative effects of multimedia on high school Chinese teaching based on investigation and research and teaching practice, and put forward some thoughts on the negative effects.