Corneal collagen cross-linking(CXL)is a photochemotherapy for keratoconus, keratectasias and infectious keratitis. Corneal collagen fiber infiltrated with riboflavin, a photosensitizer which generates reactive oxygen species when activated by UVA at 370nm, was induced to form the crosslinks in corneal stroma. Corneal collagen cross-linking alone or combined with medicine therapy could be used to treat fungal keratitis, improve the cure rates, and reduce the complications and the demands of corneal transplantation surgery. The purpose of this paper is to review the basic principle, procedure, laboratory researches, clinical applications and the safety about this treatment.