Persistent corneal epithelial defect(PED)can occur after corneal herpes simplex virus infection, corneal transplantation, and intraocular surgery in diabetic patients. Although the incidence is not high, it can cause serious consequences if not properly managed, such as corneal infection or exacerbation, stromal ulcers, perforation, scarring, and even loss of vision. The pathogenic causes of PED are diverse and can be mediated by multiple mechanisms. In clinical practice, even with aggressive treatment, the corneal epithelium in PED eyes is difficult to heal and presents a challenge for treatment. At present, the standard treatment for PED management mainly includes the use of bandage soft contact lenses and artificial tears, aiming at the barrier protection for the corneal epithelium. The new treatment mainly focuses on epithelial regeneration and corneal nerve re-innervation. In addition, several drugs and methods with potential therapeutic value have emerged in recent years. In this review, we talk about how are the PEDs spread, what causes them, how are they diagnosed and how are they treated. We also talk about some new therapies and research process.