In contrast to SLE, ankylosing spondylitis (AS) has been thought to be a predominantly male disease; the prevalence of AS is indeed significantly higher in men than in women, with a ratio of 2.5 to 5:1, and the disease is relatively milder in women, making it easier to underdiagnose. There is no satisfactory explanation for the difference in the prevalence of AS in both sexes, and there is no significant effect of occupation and pregnancy on the disease, and the relationship with sex hormones is uncertain. Compared with male AS, it is generally believed that the onset of the disease is later in women than in men, with different reports about 3-6 years later. The incidence of peripheral joint involvement, especially in the knee, is significantly higher in women than in men. X-rays show more involvement of the lumbar spine, cervical spine, hip joint and the whole spine in men. For example, intervertebral bone bridge formation/spinal joint-like changes account for 1/3 of the male group, while women only account for 1/10, which shows that women’s disease is indeed less serious than men’s and the disability rate is much lower than that of men. Attention to the differences between female AS and male AS will not only facilitate the diagnosis and differential diagnosis, reduce missed diagnosis and misdiagnosis, but will also provide useful clues for in-depth study of the disease.