A meta-analysis and systematic review evaluated the efficacy of Cangfu Daotan decoction combined with Diane-35 in the treatment of polycystic ovary syndrome with mucus wetness (PCOS). They included 16 randomized controlled trials comparing combination therapy with Diane-35 alone. Combination therapy significantly improved the overall effective rate (RR = 1.24, 95% CI 1.18–1.31, p < 0.00001). It reduced serum testosterone (MD = −0.26, 95% CI −0.37 to −0.15, p < 0.00001), luteinizing hormone (MD = −1.64, 95% CI −2.46 to −0.82, p < 0.0001), follicle-stimulating hormone (MD = −1.11 to −0.13, p = 0.01) and ratio LH/FSH (MD = –0.27, 95% CI –0.43 to –0.12, p = 0.0006). BMI was also reduced (MD = -1.55, 95% CI -3.06 to -0.04, p = 0.04). Funnel plots did not show publication bias, the risk of bias was higher due to lack of blinding and concealment. Evidence is limited by methodological shortcomings and heterogeneity, large RCTs are needed.