1. Day 1 after surgery: ankle pump exercises as much as possible. Quadriceps isometric exercises anterior thigh muscle tensing and relaxation exercises, do more without increasing pain. You can walk on crutches, but the affected limb should be protected by a 30° bent knee brace, and the total walking time on the ground should not exceed 20 minutes per day. 2.Postoperative day 2~7: Continue the above exercises. Continue the brace fixation, and gradually extend the total daily walking time to 20~40 minutes. 3.Week 2~3 after surgery: Continue the above exercises. Continue to fix the brace and do not remove it even when sleeping, and gradually extend the total walking time to 1~2 hours per day. Start straight leg raising exercise: straight knee joint extension, straight leg raising until the heel is 15cm from the bed, hold until exhaustion. 10~20 times/day. 4. 4th postoperative week: continue the above exercises. Remove the splint or brace for 30 minutes each day to practice knee flexion from 0°~50°. 5.Postoperative week 5: Continue the above exercises. Flexion exercises to the range of 0°~90°, and the brace can be removed at night for sleeping. 6.Postoperative week 6: Continue the above exercises. Flexion exercises to 0°~110° range. 7.Postoperative week 7: Afterwards, remove the brace and you can engage in all normal daily activities. Continue the knee flexion exercises every day until it is close to normal.