This is a randomized, double-blind, placebo-controlled, multicenter clinical trial in participants with moderate-to-severe plaque psoriasis .

Inclusion Criteria:

1. Subject voluntarily takes part in the study after being fully informed,signs a written ICF, and agrees to follow procedures specified in the study protocol;
2. Plaque psoriasis assessed by the investigator as suitable for systemic treatment and stable (defined as stable as no significant outbreak of morphological change or disease activity assessed by the investigator) for at least 6 months prior to signing informed consent;
3. During the screening period and before taking the investigational drug for the first time, psoriatic surface area (BSA) ≥10%, PGA score ≥ 3, PASI score ≥ 12;
4. Hematology, Blood chemistry and Urinalysis examination were basically normal.

Exclusion Criteria:

1. Erythrodermic psoriasis, pustular psoriasis, guttate psoriasis, reverse psoriasis, drug-induced psoriasis;
2. Have other skin lesions that affect the evaluation of treatment outcomes, such as eczema;
3. History of herpes zoster/herpes simplex, or presence of herpes zoster/herpes simplex infection during the screening period;
4. Have a history of tuberculosis, or active tuberculosis, or latent tuberculosis, or suspected clinical manifestations of tuberculosis infection;
5. Other conditions that the investigator considers inappropriate for participation in the study.