Both Qing-Ying decoction (QYD), a Traditional Chinese Medicine (TCM), and secukinumab, a fully humanized anti-interleukin-17A monoclonal antibody, have been used to treat patients with plaque psoriasis. The combined application of TCM and biologics in the treatment of psoriasis, however, has not been investigated. We enrolled a total of 68 patients with plaque psoriasis in our prospective study, and randomly assigned them to either the study group (treated with secukinumab plus QYD), or the control group (treated with secukinumab alone). After 12- and 16-week treatment, the Psoriasis Area and Severity Index (PASI) score and the TCM score were significantly reduced in both the study and the control groups. However, the reduction in PASI and TCM scores was more significant in the study group than in the control group (12-week: PASI: 5.29 ± 0.27 vs 8.87 ± 0.38, respectively; P < .01; TCM: 5.83 ± 0.21 vs 12.39 ± 1.23, respectively; P < .01; 16-week: PASI score: 4.76 ± 0.18 vs 8.36 ± 0.31, respectively; TCM score: 4.98 ± 0.19 vs 11.27 ± 1.13, respectively; P < .01). The total treatment efficacy rate was significantly higher in the study group (97.1%) than the control group (76.5%; P = .012). The number of CD3+ and CD4+ T cells was increased, while the number of CD8+ T cells was decreased after treatment in both groups, with more significant changes in the study group (P < .01). QYD may enhance the therapeutic outcome of secukinumab in the treatment of plaque psoriasis by further suppressing chronic skin inflammation, as well as reducing adverse events and patients' psychological stress.