Ankylosing spondylitis often occurs in young people. It not only causes spinal stiffness and retrognathism, but also often involves the hip joint, causing ankylosis and fusion of the hip joint in severe cases, which can seriously affect the quality of life and even disability. Most of these patients are young people, and total hip replacement is too early for them, while hip surface replacement provides a chance for these patients to have a new life and create conditions for future hip revision. The patient was diagnosed with: ankylosing spondylitis, he was already unable to bend over, had a posterior spine protrusion, hip muscle atrophy, and was unable to move his hip joint, and could not even do his bowel movements alone in life. The patient was young, and conventional total hip replacement (THA) had the disadvantage of bone loss and multiple revisions, while surface hip replacement (resurfacing) had great advantages because it preserved most of his own bone. Patients avoid tonic fusion of the hip joint after resurfacing, joint mobility is greatly restored, and their own bone is protected, which is a good choice for such patients.