Consider congenital hip dislocation, fracture, femoral head necrosis, osteoarthritis of the knee, etc., and give the brace fixation, traction, surgical treatment. For congenital hip dislocation, X-ray of the pelvis should be taken first. If it is mildly dislocated, pelvic support can be used to fix and correct the dislocation. If the hip joint is completely dislocated, surgery is needed to correct the dislocation, and after the operation, the hip joint is immobilized by plaster or brace, and the anterior tilt angle of femoral neck and the neck stem angle are regularly rechecked. Fracture, caused by the unequal length of both lower limbs, children should be skin traction or surgery, adults usually bone traction or surgery. Necrosis of the femoral head, caused by the collapse of the femoral head resulting in shortening of the lower limbs, it is recommended to carry out hip joint replacement surgery, and early postoperative hip joint functional exercises. Knee osteoarthritis, generally for the knee internal deformity, can cause the affected limb shortening, it is recommended to carry out knee replacement surgery, early postoperative functional exercise of the knee joint. Unequal length of both lower limbs is recommended to actively seek medical advice, treatment under the guidance of a physician.