Inclusion Criteria:

• Aged between 30 and 75 years, regardless of gender
• Diagnosed with Parkinson's disease conforming to relevant clinical diagnostic standards with a medical history of 5-20 years
• Having received standard anti-PD treatment and been given optimal anti-PD treatment under the guidance of the investigator, but the efficacy has significantly declined
• Good response to levodopa medications, the levodopa challenge test (LCT) shows that the maximum improvement rate of the UPDRS-III score exceeds 30%
• The modified H&Y staging (Off period) of ≥2.5 and ≤4, with total daily "off" time >2 hours
• Stable dose of anti-Parkinson' disease drugs for at least 4 weeks prior to screening
• Good physical condition or stable concomitant diseases

Exclusion Criteria:

• The subjects with atypical Parkinson's syndrome or secondary Parkinson's syndrome
• Severe systemic diseases or functional impairments
• Evidence of active infection or chronic infection, which may pose a risk to the subject
• Severe concomitant central nervous system diseases or severe cognitive and psychiatric disorders
• Subjects with a history of brain injuries, cerebral vascular malformations, hydrocephalus, brain tumors, or other brain damages as shown by previous Head CT/MRI scans, or subjects with abnormal brain imaging in the striatum or other brain regions that significantly increase surgical risks
• Subjects who have participated in clinical trials for stem cell therapy or gene therapy for Parkinson's disease, or have participated in other interventional clinical trials within the last 3 months
• Subjects with a history of severe allergies or hypersensitivity reactions, known hypersensitivity to the investigational drug or its ancillary materials, or intolerance to them
• Pregnant or breastfeeding women