A 47-year-old man presented with binocular diplopia and hypertropia of left eye for 2 months. He was diagnosed with Graves’ disease for half a year. The patient was protruding in both eyes with hypertropia and limited of infraduction in left eye. Therefore, the patient was admitted to our ophthalmology department with the diagnosis of thyroid-associated ophthalmopathy. After admitting to hospital, binocular diplopia and left eye hypertropia grew worse by the end of the day or after exertion, and improved in the morning of the day or upon rest. Combining with the orbital MRI results, the patient was considered with ocular myasthenia gravis. The related examination of ocular myasthenia gravis was performed. The following test results were: neostigmine test (+), acetylcholine receptor antibody (+). Therefore, the patient was diagnosed with thyroid-associated ophthalmopathy combined with ocular myasthenia gravis. The patient had marked improvement after treatment with pyridostigmine and oral glucocorticoid.