Painful ophthalmoplegia syndrome, the Tolosa-Hunt syndrome(THS), is characterized by unilateral involvement of the IIIrd, IVth and VIth cranial nerves, as well as supra- and retro-orbital pain. The etiology is unknown, possibly related to immunodeficiency reaction, also, some scholars believe that it is related with non-specific inflammation of the superior orbital fissure or vascular lesions. The ocular symptoms vary depending on the scope, impact and severity degree of the nerve. Painful ophthalmoplegia syndrome is rare in clinic and easily misdiagnosed as ophthalmoplegic headache. Clinical diagnosis is difficult, while adrenal cortical hormone is effective in treatment. We made a review on the etiology, clinical characteristics, diagnosis, differential diagnosis and treatment of painful ophthalmoplegia syndrome.