The teaching reform of “Triple independent” in college physical education has been implemented in Colleges and universities all over the country since 2003. The serious problems of “students' physical health level is still the obvious short board of students' quality,”¹“poor eyesight and physical health level are still the short board of students' quality” have not been overcome and solved.² It is of great significance to study the birth and development mechanism of students' short physical health level for enhancing students' physical fitness and promoting the healthy development of teenagers. According to the idea that the connection between causes and results is the connection between things or phenomena, the retrospective perspective based on the “Triple independent” teaching mode of sports and the experience and practice beyond “point” and “level” are adopted. Based on the characteristics of “Triple independent” teaching mode and the problems existing in the implementation of “Triple independent” teaching mode and the countermeasures to solve the problems, two explanatory variables of “Triple independent” freedom and project diversity of students are extracted. Through the analysis of the two explanatory variables caused by the qualitative comparative analysis method, it is concluded that the main position of “Triple independent” of students is the effective condition configuration that causes the short board of students' physical health level. The results show that the contradiction between the students' independent choice of curriculum content and the setting of sports events, the contradiction between the students' independent choice of teachers and PE teachers are the main contradiction of the “Triple independent” Teaching mode and the root of the defect of the “Triple independent” Teaching mode. The crux of the teaching reform of “Triple independent” lies in the understanding and interpretation of the subject status of students' Triple independent. The teaching mode of “Triple independent” in physical education is to teach students in the main position of “Triple independent”. The virtual teaching objectives and the lack of depth in teaching are the reasons for the short physical health level of students. The teaching reform of “Triple independent” in Physical Education in Colleges and universities, whose form is greater than content, is the reform of teaching methods, not the reform of teaching content.