Ankylosing spondylitis (AS) is a systemic autoimmune disease characterized by chronic inflammation of the sacroiliac and spinal joints. The disease is most common in young adult males, with a peak age of onset in the 20s and 30s. The early stage of the disease is often characterized by low back pain, and as the disease progresses, fibrous or bony ankylosis of the spine and peripheral joints may develop, resulting in deformity or disability. Foreign reports suggest that patients with AS can lose most of their function within 10 years of onset and need to stop working after 15.6 years. Traditional pharmacological treatment includes NSAIDs and slow-acting drugs such as lorazepam and thalidomide (Response Stop), with less certain efficacy. Tumor necrosis factor (TNF)-a is a key link in the pathogenesis of AS. Basic research has found that TNF-a has a role in mediating inflammation and immunomodulation in the immune response, and anti-TNF-a biologics such as infliximab, etanercept and adalimumab have been clinically proven to be effective and have been called a leap and revolution in the history of AS treatment.