Objective: The etiology and clinical characteristics of patients with binocular diplopia as main symptom were investigated using retrospective analysis method. Methods: The clinical data of patients with binocular diplopia treated in department of ophthalmolog y, affiliated hospital of Weifang Medical University from January 2021 to March 2022 was summarized and the etiology and clinical characteristics retrospectively. Results: There were totally 29 patients, 16 males and 13 females, aged from 17 to 81 years, with an average of (59 ± 14) years; among them, there were 8 cases derived from vascular factors, including 5 cases with cerebrovascular disease, 2 cases with posterior communicating artery aneurysm and 1 case with internuclear ophthalmoplegia. There were 8 cases derived from inflammatory and immune factors, including 4 cases with myasthenia gravis, 2 cases with Tolosa-Hunt syndrome, 1 case with hypertrophic meningitis and 1 case with inflammatory pseudotumor. There were 9 cases derived from endocrine factors, including 5 cases with peripheral neuropathy in diabetes and 4 cases with thyroid related ophthalmopathy. There were 2 cases derived from tumors, including 1 case with oculomotor schwannoma, 1 case with orbital MALT lymphoma and there were 2 other cases of trauma. Conclusions: The etiology of binocular diplopia is complicated and the clinicians should pay attention to the screening of systemic diseases of patients refer to the principle of localization diagnosis first and qualitative analysis next so as to improve the diagnostic accuracy and reduce the misdiagnosis rate.