The knee joint is a very important joint in the human body, there are many kinds of knee injuries and different surgical methods, post-operative rehabilitation is also different, now I will briefly explain the rehabilitation of ACL and posterior cruciate ligament injuries after surgery or replacement surgery. The anterior cruciate ligament mainly serves to prevent the tibia from moving forward, and the posterior cruciate ligament prevents the tibia from moving backward. Both must be practiced at the same time, the specific training methods need to be based on each patient’s degree of injury and surgical methods, the specific time of fixation and rehabilitation intervention by orthopedic surgeons rehabilitation physicians and therapists to consult the development of rehabilitation programs.