This is a multicenter, randomized, double-blind, placebo-controlled, phase III clinical study which is designed to determine the efficacy, safety, immunogenicity and pharmacokinetics, and pharmacodynamics of HB0017 Injection in the treatment of moderate to severe plaque psoriasis in adults.

Inclusion Criteria:

• Male or female subjects aged 18-75 years (inclusive)
• Chronic plaque psoriasis (PSO) for at least 6 months prior to the Randomization.
• Psoriasis Area Severity Index (PASI) >=12 and body surface area (BSA) affected by PSO >=10% and Static Physician Global Assessment (sPGA) score >=3.
• Subjects who are suitable for systemic treatment or phototherapy for psoriasis as judged by the investigator
• Subjects who are able to use effective contraception from the screening period to 6 months after the last dose

Key Exclusion Criteria:

• Forms of psoriasis other than chronic plaque-type (e.g., pustular, erythrodermic and/or guttate psoriasis) at screening or baseline
• Drug-induced psoriasis
• Ongoing use of prohibited treatments
• Any active infection (other than common cold) within 14 days
• Serious infection defined as requiring hospitalization or iv anti-infective(s) within 1 month prior to randomization
• Have previously received any drug that directly targets IL-17 or IL-17 receptor
• Have concurrent or recent use of any biologic agent within the following washout periods: etanercept <28 days; infliximab and adalimumab <60 days; golimumab < 90 days; anti-IL-12/anti-IL-23 or anti-IL-23p19 antibody drugs <6 months; or other anti-psoriatic therapy not listed herein within its 5 half-lives prior to randomization
• A history of inflammatory bowel disease or other serious autoimmune disease
• Previously diagnosed with serious mental illness such as anxiety, depression or suicidal tendency