This is a multicenter, randomized, double-blind, parallel-group, placebo-controlled, fixed-dosed phase II clinical study to evaluate the efficacy and safety of LY03020 in chinese acutely psychotic adult subjects with schizophrenia.

Inclusion Criteria:

• Subjects and their guardians sign informed consent voluntarily.
• Male or female subject aged 18 to 65 years (inclusive).
• Subject meets DSM-5 criteria for schizophrenia and confirmed using the Mandarin for China Translation Version 7.0.2).
• According to the investigator's assessment, subject has an acute exacerbation or relapse of schizophrenia requiring hospitalization (no longer than 2 months). Continuing hospitalization does not exceed 2 weeks for patients with acute psychotic exacerbation or relapse that require the hospitalization prior to screening.
• Subject must have a PANSS total score ≥ 80 and a PANSS item score ≥ 4 (moderate) on 2 or more of the following PANSS items: delusions(P1), conceptual disorganization(P2), hallucinations(P3), and suspicion, victimization (P6) at screening and baseline.
• Subject must have a CGI-S score ≥ 4 at screening and baseline.

Exclusion Criteria:

• - Subject who has a history or presence of symptoms consistent with a major psychiatric disorder other than schizophrenia as defined by DSM-5;
• According to the investigator's assessment, subject has a treatment-resistant schizophrenia;
• Subject who has a history or presence of symptoms consistent with neuroleptic malignant syndrome (NMS);
• Subject has received electroconvulsive therapy treatment within 3 months prior to screening or is expected to require ECT during the study;
• History of suicide attempts (including actual attempts, interrupted attempts, or failed attempts) within 1 year prior to screening or suicidal ideation within 6 months prior to screening, defined as affirmative responses ("yes") to question 4 or 5 on the Columbia-Suicide Severity Rating Scale (C-SSRS) at screening/baseline;
• History or presence of the following treatments:

Within 1 week prior to randomization or within 5 half lives (whichever is longer), subject has been treated with short acting antipsychotic drugs or other psychoactive drugs (such as antidepressants, mood stabilizers, and antiepileptic drugs), except for anti-anxiety drugs or sedative hypnotic drugs that can be used according to the protocol; Within two treatment cycles prior to randomization, subject has used long-acting antipsychotic drugs; Within 4 weeks prior to randomization, subject has used monoamine oxidase inhibitors (MAOIs); Previously used sufficient amounts and periods of clozapine for the treatment of schizophrenia;

• Congenital long QT syndrome; uncontrolled or severe cardiovascular disease, including NYHA class II or higher congestive heart failure, unstable angina, myocardial infarction within 6 months prior to screening, or presence of treatment-requiring severe arrhythmias (e.g., sustained ventricular tachycardia, ventricular fibrillation, torsades de pointes) at screening; resting heart rate <50 beats per minute (bpm) and the abnormality has clinical significance according to the researchers' assessment at screening/baseline; or QTc >450 ms (male) / QTc >460 ms (female) based on Fridericia's formula-corrected measurements and the abnormality has clinical significance according to the researchers' assessment at screening/baseline;
• Subjects experienced a history of keratopathy, fundus disease, increased intraocular pressure, or angle-closure glaucoma;.
• Subjects with a history of orthostatic hypotension or syncope.