I. Muscle strength (1, 2, 3 shall be started immediately after the anesthesia subsides after surgery, continue training for 8 weeks to prevent thrombosis and muscle atrophy) 1. Ankle pump exercises: hook the toe upward with maximum force for 5 seconds and then step downward for 5 seconds, total 500-1000 times per day. 2.Quadriceps contraction: start immediately after surgery. Contract the anterior thigh muscle with force for 5 seconds and then relax for 2 seconds, total 500 times per day. 3.N-string muscle contraction: after the knee joint is completely straight, press down the pillow under the foot with force for 5 seconds, relax for 2 seconds, total 500 times per day. 4.Straight leg lift exercise: finish within 1 day after surgery. Knee joint fully straightened and lifted 15 ° from the bed, a total of 30 times a day, each time until exhaustion. 5.Static squat exercises: zigzag stance, starting 10 weeks after surgery, practicing at a painless angle, taking care that the knee joint does not exceed the toes, lasting 1~2 minutes each time. 2. Joint angle 1. Patients with meniscus repair: start flexion exercises 3 days after surgery to reach as large an angle as possible with slight pain, reaching 90° 1 week after surgery and 120°~130° 2 weeks after surgery. 2.Patients with meniscus suture: if the posterior horn and body are sutured, flexion exercises should be started 1 week after surgery and reach 90° 2 weeks after surgery, but deep squatting is prohibited within 4 weeks after surgery; attention should be paid to prevent active knee extension and prohibit violent knee extension within 2 weeks after surgery for the anterior horn. 3. 8~12 weeks after surgery, the joint flexion and extension activities should be the same as the healthy side, and there is no pain. 1. Patients with meniscus repair can walk with full weight on the first day after surgery, paying attention to uniform and symmetrical gait. 2. Patients with meniscus suture: if the posterior and anterior corners are sutured, they can resume walking with weight 2 weeks after surgery, and can walk with partial weight within 2 weeks; if the body is sutured, they can walk with partial weight 2 weeks after surgery, and gradually walk with full weight 4 weeks after surgery.