The rapid development of the Internet has injected new thinking into modern physical education teaching, making the informatization construction of physical education teaching a pivotal way to break the traditional teaching limitations and give full play to the function of physical education. Based on the modern teaching theory, this study analyzes the informationized teaching mode of physical education in colleges and universities and the availability of teaching resources. Adopting principal component analysis method, combining KNN-ADPC clustering algorithm and introducing K nearest neighbor idea, this paper aims to explore the key factors affecting the effect of sports informatization teaching in colleges and universities. The sports informatization teaching in specific colleges and universities is selected as a research case, and the fuzzy qualitative comparative analysis method is used to conduct an in-depth study. The study results show that students’ sports cognition and teachers’ professionalism are essential requisites affecting the effectiveness of sports informatization teaching, with the consistency of the two being close to 0.9. The effectiveness of sports informatization teaching is mainly affected by the third configuration, with a coverage rate as high as 83.4%, in which teachers’ professionalism is proved to be the most critical influencing factor. The conclusion of the study points out that to effectively enhance the development of physical education informatization teaching, the professional training of teachers and the cognitive ability of students in sports should be strengthened, as well as to improve the physical education teaching environment and to create a positive physical education cultural atmosphere.