Introduction: The speed and quality of functional recovery after knee cruciate ligament reconstruction directly affect the training effect and competition results of athletes. Objective: To evaluate the effect of early systematic rehabilitation after reconstruction of ligament tears in outdoor sports athletes. Methods: In this study, Liu Mou, an outstanding player of the national men's rugby team, was selected as the experimental object. A rehabilitation training program was adopted, and rehabilitation began from 2 to 5 weeks after reconstruction. Results: After the recovery of the first stage for 4 weeks, the knee extension Angle of the injured limb in Liu's sitting position reached 180 degrees. In the second stage of rehabilitation physical training, the body composition test showed that body fat decreased from 20.8% before rehabilitation to 16.3%. At the end of the third stage of physical training, he could complete the high flip. Conclusions: Through different stages of postoperative rehabilitation physical training, Liu's physical condition fully recovered to a higher level. He could then participate in normal football training and return to the game, indicating that Liu's rehabilitation training after anterior cruciate ligament reconstruction is effective. Level of evidence II; Therapeutic studies - investigation of treatment results.