Abstract： Objective： To observe the clinical effect of modified Xijiao Dihuang Decoction combined with Secukinumab Injection for moderate to severe psoriasis with blood heat syndrome. Methods：A total of 64 cases of patients with moderate to severe psoriasis with blood heat syndrome were selected and divided into the control group and the observation group according to the random number table method，with 32 cases in each group. Two cases were excluded in both group，and finally 30 cases were included. The control group was treated with Secukinumab Injection， and the observation group was additionally treated with modified Xijiao Dihuang Decoction based on the treatment of the control group. Both groups were treated for 2 months. The clinical effects，the Psoriasis Area Severity Index（PASI) scores，the Dermatology Life Quality Index (DLQI) scores，the levels of inflammatory factors and the incidence of adverse reactions were compared between the two groups. Results：After treatment，the total effective rate was 93.33% in the observation group， higher than that of 73.33% in the control group， the difference being significant (P＜ 0.05). The scores of PASI and DLQI in the two groups were decreased when compared with those before treatment，and the above two scores in the observation group were lower than those in the control group， differences being significant (P＜0.05). The levels of interleukin-6 (IL-6)， interleukin-17A (IL-17A)， and interleukin-23 (IL-23) in serum in the two groups were decreased when compared with those before treatment，and the above three levels in the observation group were lower than those in the control group， differences being significant (P＜0.05). The incidence of adverse reactions was 6.67% in the observation group and 3.33% in the control group，there being no significant difference between the two groups (P＞ 0.05). Conclusion： The additional application of modified Xijiao Dihuang Decoction based on Secukinumab Injection for moderate to severe psoriasis with blood heat syndrome can improve the clinical effect and the quality of life of patients and inhibit the inflammatory responses，with good safety.