Patients are usually advised to start early rehabilitation exercises as soon as possible under the guidance of their doctors around 1-3 days after knee surgery. Early and effective functional exercises after knee surgery can improve local blood circulation, enhance muscle strength, prevent tendon and joint capsule adhesions and contractures, and help restore normal joint and limb function. Under normal circumstances, early rehabilitation exercises for the knee joint, such as knee extension, ankle dorsiflexion and leg press, are recommended to be started 1-3 days after surgery to promote blood return to the leg. In the absence of pain 3-14 days after surgery, recovery exercises, such as straight leg raising, can be started to prevent adhesions in the periarticular tissues, to improve joint movement and to promote functional recovery for daily living needs. After 2 weeks of surgery, healing period exercises were performed, and standing exercises were performed by relying on a walking frame. When patients perform functional exercises after knee surgery, they must do so under the guidance of a professional physician and abide by the principle of gradual progress, and perform functional exercises of the limbs as their condition allows to avoid accidents.