Abstract Background During the course of their illness, people with Parkinson’s disease may see changes in their insulin-like growth factor (IGF-1) and serum homocysteine (Hcy) indices. In this study, patients with intermediate to severe Parkinson’s disease were examined for how Resagiline and levodopa and benserazide hydrochloride affected their motor performance, serum levels of homocysteine (Hcy), and insulin-like growth factor (IGF-1). Methods From June 2020 to December 2021, a total of 100+ cases of Parkinson’s patients over 60 years old in the middle and late stages of Parkinson’s were seen in the outpatient and inpatient departments of the Third People’s Hospital of Chengdu City and had a detailed observation record, and according to the inclusion criteria, the patients who met the criteria were randomly grouped into a clinical observation group and a control group. The subjects in the control group received only levodopa and benserazide hydrochloride treatment, while the observation group was treated with Resagiline in combination with the clinical control group. The total treatment observation period was 1 year for both groups, and the motor function and serum Hcy and IGF-1 indexes of both groups were compared after the end of treatment. Results We randomly and evenly grouped 64 patients who met the requirements of the inclusion criteria into a clinical observation group and a control group, each with 32 patients, from among 168 patients over 60 years of age with detailed observation records in the middle and late stages of Parkinson’s. After the 1-year observation period, we found that the total effective rate after treatment in the clinical observation group (93.75%) and significantly higher than that in the control group (68.75%) (P < 0.05); after 1 year of treatment, the UPDRS score decreased in both groups, and the observation group was significantly lower than the control group (P < 0.05); after treatment, serum Hcy decreased and IGF-1 increased in both groups, and the observation group was higher than the control group mean values (P < 0.05). Conclusions In patients with Parkinson’s disease who are in the middle and late stages of the disease, the administration of Resagiline combined with levodopa and benserazide hydrochloride can significantly lower the body’s serum Hcy level, significantly raise IGF-1 levels, and significantly improve motor function in patients with Parkinson’s disease. It can also have significant therapeutic effects.