Hundreds of randomized controlled trials (RCTs) on tripterygium glycosides tablet (TGT) in the treatment of ankylosing spondylitis (AS) have been published, but the therapeutic effects have never been systematically reviewed yet. The aim of this meta-analysis was to evaluate the efficacy of TGT on AS based on RCTs. PubMed, ScienceDirect, Cochrane Library, China Journals Full-text Database, and Wanfang Data were searched. The RCT quality was evaluated by the Cochrane Collaboration's tool for assessing risk of bias. The RCT characteristics including publication years, sample sizes, and follow-up periods as well as outcome measures including symptoms improvement, morning stiffness (MS), bath ankylosing spondylitis patient global score (BAS-G), pain index (PI), swelling index (SI), finger to floor distance (FFD), pillow wall distance (PWD), Schober test (Schober), erythrocyte sedimentation rate (ESR), and C reactive protein (CRP) were extracted. The odds ratio (OR), mean difference (MD), and its 95% confidence interval (CI) were selected for overall effect sizes. Subgroup, sensitivity, and meta-regression analyses were conducted to confirm the results. Eleven RCTs with 807 participants were included, the quality of which was moderate. OR of TGT in treating AS was 0.46 (95% CI 0.24, 0.90]. MD of MS was 11.79 (95% CI 3.13, 20.45). MD of BAS-G was 0.13 (95% CI -19.73, 19.99). MD of PI was 0.78 (95% CI 0.22, 1.34). MD of SI was 0.80 (95% CI 0.06, 1.53). MD of FFD was 0.80 (95% CI 0.06, 1.53). MD of PWD was 1.37 (95% CI -0.64, 3.38). MD of Schober was -0.36 (95% CI -0.65, -0.07]. MD of ESR was 4.58 (95% CI 2.10, 7.06). MD of CRP was 1.86 (95% CI -2.03, 5.76). Subgroup, sensitivity, and meta-regression analyses found the robust results. In conclusion, TGT could not treat AS effectively, as suggested by the moderate RCT quality and meta-analysis evidence.