Corneal ulcer is a common ocular surface disease. The main symptoms include decreased vision, eye pain and photophobia. In severe cases, it can cause corneal perforation or even enucleation. It greatly affects the patient′s quality of life. Although unilateral occurrence is the norm, bilateral corneal ulcers have been observed with unfavorable prognoses. This review aims to explore the pathogenesis and risk factors of bilateral corneal ulcer through analysis of cases of corneal ulcers in both eyes to provide theoretical guidance for early diagnosis, prevention, and treatment of bilateral corneal ulcer. The purpose is to avoid more patients with visual impairment as much as possible, and reduce the social and economic burden.