• Clinically diagnosed patients with primary Parkinson's Disease \[in accordance with the Diagnostic Criteria for Parkinson's Disease in China released in 2016\];

• Participants must be able to comprehend (fully understand the details of the clinical trial and the potential risks and benefits of the study) and voluntarily sign the informed consent form. When participants are unable to read, the informed consent form and other written materials may be read by a legal representative or an impartial witness, who will also witness the consent process;

• Age between 40 and 70 years old, inclusive, regardless of gender;

• Body weight between 40 kg and 110 kg, and Body Mass Index (BMI) between 18 kg/m² and 34 kg/m²;

• A history of Parkinson's Disease for \>= 5 years;

• Able to undergo surgical anesthesia, suitable for neurosurgical procedures under anesthesia, and capable of undergoing CT/MRI examinations;

• Hoehn-Yahr stage (Appendix IV Hoehn-Yahr Staging) at screening in the off state is 4-5 (including borderline values);

• MDS-Unified Parkinson's Disease Rating Scale Part III Motor Examination (MDS-UPDRS-III) score in the off state \>= 30; and a positive levodopa challenge test (improvement in UPDRS-III score from off to on state \>30%);

• Patients whose PD symptoms cannot be effectively controlled or who experience intolerable adverse drug reactions despite treatment with medications recommended by the Chinese Guidelines for the Treatment of Parkinson's Disease (4th Edition)-2020;

⁃ Receiving a stable dose of anti-Parkinson's medication for at least 4 weeks prior to administration;

⁃ Acceptable laboratory values during the screening period and prior to administration (Day 0): a) Hemoglobin \>= 100 g/L; b) Platelets \>= 100×10\^9/L; c) Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) \<= 1.5 times the upper limit of normal; d) Total bilirubin \<= 1.5 times the upper limit of normal; e) Serum creatinine (Cr) \<= 1.5 times the upper limit of normal;

⁃ Participants agree not to receive any other therapeutic intervention studies during the main study phase;

⁃ Participants agree not to participate in any other clinical studies during the study period;

⁃ Participants agree not to receive any other vaccines within 30 days after administration;

⁃ Participants must have the ability to live independently or the ability to clearly delegate relevant caregivers, with good compliance, and be able to attend regular follow-ups. During follow-up, participants must accurately complete the PD patient diary, and family members, guardians, or caregivers may assist in filling out the patient diary;

⁃ Participants must have a pre-existing neutralizing AAV8 antibody titer \<= 1:90 as determined by testing;

⁃ Based on the judgment of the Principal Investigator (PI), cancer-related screening will be conducted for patients who meet the inclusion criteria.