Objective: To compare the curative effect of tumor necrosis factor (TNF) antagonist and interleukin 17 (IL-17) in ankylosing spondylitis (AS) and their effects on patients’ immune function. Methods: A retrospective analysis was performed on the data of 244 patients with AS. According to different medication methods, patients were divided into TNF antagonist group (n=196, adalimumab) and IL-17 antagonist group (n=45, secukinumab). The disease activity and function \[AS Disease Activity Score (ASDAS), Bath AS Functional Index (BASFI) and Bath AS Disease Activity Index (BASDAI)\], clinical symptoms \[Visual Analog Scale (VAS) scores for lower back and nighttime pain and duration of morning stiffness\], serological indicators \[C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), white blood cell count (WBC)\], immune function \[immunoglobulin G (IgG), IgA and IgM\], and incidence of adverse reactions before treatment, after 4 and 24 weeks of treatment were compared between the two groups. Results: After treatment, ASDAS was lower, and BASFI was higher in TNF antagonist group(P<0.05). The changes in pain degree at low back and night, and the duration of morning stiffness were more significant in TNF antagonist group after 4 weeks of treatment, while the above changes were more significant in IL-17 antagonist group after 24 weeks of treatment(P<0.05). After 4 and 24 weeks of treatment, the levels of CRP, ESR, and WBC in both groups decreased(P<0.05), and the levels of CRP and ESR in the TNF antagonist group were lower than those in the IL-17 antagonist group(P<0.05). The IgG level in the TNF antagonist group decreased (P<0.05) and was lower than that in the IL-17 antagonist group(P<0.05). There was no statistically significant difference in the occurrence of adverse reactions between the two groups(P>0.05). Conclusion: Adalimumab has short onset time and better improvement effect on immune function and biochemical indexes, while secukinumab is more beneficial to improve clinical symptoms in patients.