After ACL reconstruction is not the recovery of joint function, but the beginning of the recovery of joint function. The following program, which needs to be adjusted according to the stability of the meniscus, must therefore be implemented in consultation with the surgeon. The rehabilitation program is as follows: Week 1: 1. Resting status: Keep the knee fully extended with 0 degrees of brace. 2. Lowering to the ground. 3. Flexion mobility: Begin exercises on the 3rd postoperative day and gradually increase to 90°, to be performed under the protection of a brace, and brace adjustment must not exceed 90°. 3-5 times a day, 10-20 minutes each time. You can choose one of the following two methods of training: (1) supine knee flexion training – the knee is straightened to 0 degrees, then gradually flexed, the heel does not leave the bed when flexing the knee, and moves on the bed surface. (2) Sitting flexion training – sitting on the edge of the bed or a high stool, the affected limb naturally drops, the lower limb of the healthy side can be used to assist in protecting and controlling the affected limb. 4.Extension training: 0 degree of support, flat on the bed surface, with pillows at the heel, so that the knee joint is suspended. 3-5 times a day, 10-20 minutes each time. 5.Active ankle flexion and extension exercise (ankle pump): ankle joint force, uniform and slow, full range of plantar flexion, dorsiflexion and extension activities, the effect is to promote blood circulation, eliminate swelling, prevent lower limb thrombosis, once every 3 hours, one group each time, each group of 30. 6.Quadriceps contraction exercise, straighten the knee joint, press the bed with N fossa and hold it for 5 seconds, then relax and repeat after a short rest, 4 times a day, 10-20 minutes each time. 7, straight leg raise training, extend the knee and keep the knee straight, raise and leave the bed, 10/15 cm, hold for 5 seconds and then slowly put down, repeat after a short rest; or lift and hold until you can’t hold on, 3 sets of exercise per day, 10 to 20 minutes per set. The second week: The training program is generally the same as the first week. At this stage, the pain and swelling are significantly reduced compared with the first week, and the intensity of plyometric training is increased as tolerated, and the time spent on the floor is appropriately increased. Light weight-bearing is allowed, and the following principles need to be followed: weight-bearing without flexion (brace 0 degrees); flexion without weight-bearing (refers to mobility training in bed).