Inclusion Criteria:  Male/female patients with early Parkinson's disease who are over 30 years old and under 75 years old (including cut-off values). Able to understand and willing to sign an informed consent form (ICF) voluntarily. The diagnosis of Parkinson's disease complies with idiopathic Parkinson's disease (2015 version of MDS Parkinson's disease diagnostic criteria). Modified Hoehn and Yahr Scale≥1, ≤2.5 points. Agree to use medically acceptable contraceptive methods throughout the study and within 1 month after completing the study.  Exclusion Criteria:  Have a history of severe allergic reactions or allergies to levodopa or carbidopa. Pregnancy or breastfeeding. Diagnosed as atypical Parkinson's disease or any known secondary Parkinson's syndrome. The investigator believes that the placebo treatment cannot be tolerated. Acute psychosis or hallucinations, using any antipsychotic to treat psychosis or clinically obvious depression. History of epilepsy or epilepsy. The history of narrow-angle glaucoma. Subjects with a history of malignant melanoma. Patients with obvious cognitive impairment. The investigator believes that there are clinically significant medical or surgical diseases and patients who are not suitable for participating in clinical trials.