Objective: To explore the main causes of oculomotor nerve palsy, providing a reference for clinical diagnosis and treatment. Methods: A total of 248 patients with oculomotor nerve palsy treated in the hospital from January 2016 to January 2018 were selected, and their causes and treatments were summarized. Results: This study found that the main causes of oculomotor nerve palsy were intracranial aneurysms, brain stem lesions, and brain inflammation. A few cases were due to viral infections and congenital oculomotor nerve palsy, while some patients had unknown causes. After treatment in our hospital, most patients experienced relief, although 12 patients died. Conclusion: The etiology of oculomotor nerve palsy is complex, and choosing appropriate drugs during treatment is challenging. Timely identification of the cause is an effective method for treatment.