Clinical studies have found that the MAOB inhibitor sellegran significantly delays the need for levodopa treatment and reduces the degree of disability. Survival time was prolonged in those who were combined with levodopa compared to those who were treated with levodopa alone. Motor dysfunction was significantly relieved in some patients with the application of sellegriline, as well as in patients who had no relief of symptoms when the drug was started. A multinational research center study of 800 patients with PD randomized to DATATOP (Deprenyl and tocopherol antioxidative therapy) suggested that sregiline alone significantly prolonged the duration of disease and delayed the use of levodopa preparations. Domestic clinical studies on sellegriline found that early application can delay the use of levodopa, has no significant selectivity for tremor, tonicity and hypokinesis, has mild adverse effects, is easily tolerated, and is a safe and effective anti-Parkinson’s disease adjuvant. In addition, silegiline may also act on the 5-hydroxytryptamine system, thereby improving the depression and anxiety symptoms that accompany Parkinson’s disease patients. The author’s study showed that silegiline significantly improved depressed mood, work and interest, retardation, psychogenic anxiety, somatic anxiety, gastrointestinal symptoms, systemic symptoms and weight loss in PD patients, and resulted in a significant decrease in the total score of the Hamilton Depression Inventory. Therefore, sellegrin is mainly used as a neuroprotective agent in early stage Parkinson’s disease patients with mild clinical symptoms, and as a symptom treatment drug to supplement levodopa treatment and enhance the efficacy of levodopa, especially for Parkinson’s disease patients with depression and anxiety symptoms. It is important to note that Slegiline should not be combined with 5-hydroxytryptamine reuptake inhibitors, such as fluoxetine (Prozac) and paroxetine (Seroquel). Combining the two has been reported to cause ataxia, tremor, hyperthermia, high/low blood pressure, palpitations, and psychiatric symptoms. If Prozac has been used, stop using it for more than 5 weeks before using Sellegrin. Due to the excitatory effect of Slegiline, it should not be taken at night as it may affect sleep. The dosage form specification of Silegiline is 5mg/tablet, and the commonly used dose is 5-10mg/day, divided into 1-2 morning and noon doses. As monotherapy, 10mg/day can be used. As an adjuvant to levodopa and for elderly people over 70 years old, 5mg/day is appropriate, while the levodopa dose should be reduced according to the situation.