Sulfasalazine is a kind of sulfanilamide antibiotic. It was used for inflammatory bowel disease, namely Crohn's disease and ulcerative colitis. It has dual effects of anti-inflammatory and antibacterial. It is not easy to absorb sulfasalazine orally. After 1970s, it was found that it can improve the joint pain, swelling and stiffness of the patients with mandatory spondylitis, and reduce the serum IgA level and other laboratory activity indexes. It is especially suitable for improving the peripheral arthritis of patients with ankylosing spondylitis, and has the effect of preventing recurrence and reducing the lesion of the disease complicated with prepigmentinitis. With the development of research, it is gradually applied to rheumatoid arthritis. Today, sulfasalazine has been widely used in the treatment of rheumatoid arthritis and spondyloarthropathy.