The purpose of this study is to objectively and standardly evaluate the clinical efficacy and safety of sequential treatment of psoriasis with traditional Chinese and Western medicine through a multi-center, randomized, double-blind, placebo-controlled trial.

Psoriasis is a chronic, recurrent, inflammatory disease. The incidence of this disease is increasing year by year, seriously affecting people's quality of life. Biologic agents have the advantages of rapid and efficient treatment of moderate and severe psoriasis, but their safety and recurrence are still seriously affect the application. Traditional Chinese medicine treatment of psoriasis has the advantages of fewer adverse reactions, low recurrence rate and improvement of patients' systemic symptoms while exerting the curative effect. The prevention and treatment of psoriasis by combining traditional Chinese and Western medicine has become the academic consensus. The sequential treatment of psoriasis with biological agents combined with Traditional Chinese medicine has a better therapeutic effect than that of single therapy. At present, the sequential treatment of psoriasis with targeted biological agents combined with traditional Chinese medicine has not been reported in the literature, and there is a lack of high-level clinical evidence to support it. Therefore, this project aims to provide evidence support for the clinical efficacy and safety of sequential treatment of psoriasis by traditional Chinese and Western medicine through a multi-center, randomized, double-blind, placebo-controlled trial.

Inclusion Criteria:

1. It conforms to the western diagnostic criteria of plaque psoriasis and the diagnostic criteria of TCM syndrome of blood heat syndrome;
2. Physician global assessment (PGA) ≥3, psoriasis area and severity index (PASI) score ≥12, and body surface area (BSA) ≥ 10% at screening and baseline;
3. Aged between 18 and 70;
4. Those who voluntarily participate in the study and sign the informed consent.

Exclusion Criteria:

1. Erythrodermic psoriasis patients, arthropathic psoriasis patients, pustular psoriasis patients;
2. There are other active skin diseases that may affect the evaluator;
3. Have systematically received other investigational drugs within 1 month;
4. Received external glucocorticoid and phototherapy within 2 weeks;
5. During a period of severe and uncontrollable local or systemic acute or chronic infection;
6. Infected persons with tuberculosis;
7. Patients with viral hepatitis;
8. Serious systemic disease; Or clinical test indicators belong to one of the following cases of patients: alanine aminotransferase or glutamic-oxalacetic transaminase increase > 1.5 times the upper limit of normal value; Creatinine increase > 1.5 times the upper limit of normal value; Any one of the major blood routine indicators (white blood cell count, red blood cell count, hemoglobin amount, platelet count) is lower than the lower limit of normal value; Or other abnormal laboratory tests determined by the investigator to be unsuitable for the study;
9. Patients with a history of malignant tumor and patients with primary or secondary immune deficiency and hypersensitivity;
10. Participants in clinical trials of other drugs within 3 months;
11. Those who have undergone major surgery within 8 weeks or will require such surgery during the study period;
12. For fertile women of childbearing age who did not use highly effective contraception from the screening period until the end of the last dose;
13. Pregnant or lactating women;
14. Persons with a history of alcohol, drug or substance abuse;
15. Persons with a serious history of mental illness or family history;
16. For other reasons, the researcher considers it inappropriate to participate in this study.