Keratitis is currently classified by etiology, such as infectious, immune, dystrophic, neuroparalytic, and exposure keratitis. Among them, infectious keratitis can be divided into bacterial, viral, fungal, echinocococcosis and chlamydia according to the different pathogenic microorganisms. (1) Bacterial keratitis is mainly caused by Staphylococcus, Pseudomonas aeruginosa, Streptococcus pneumoniae and other pathogenic bacteria. Due to the change of the pathogenic species, the first-line medication is also changing. Currently, Staphylococcus epidermidis-infected keratitis is increasing year by year, with an increased detection rate of Micrococcus, suggesting a trend toward an increased proportion of infections with conditionally pathogenic bacteria. The initial diagnosis of bacterial keratitis can be treated with broad-spectrum antibiotics based on clinical presentation, severity of ulceration, and then adjusted according to bacterial culture + drug sensitivity. vancomycin ophthalmic solution is preferred for Gram’s-positive bacterial infections, aminoglycoside ophthalmic solution is preferred for Gram’s-negative bacterial infections, fluoroquinolone ophthalmic solution for Gram ‘s negative bacteria and many Gram’s positive bacteria have antibacterial effects, and they also have effects on drug-resistant staphylococci. However, it is believed that the use of fluoroquinolone antimicrobials alone is likely to lead to drug resistance, and single use should be avoided as much as possible. The frequency of drug administration can be adjusted according to the severity of the infection, with frequent dosing in severe cases, and ophthalmic ointment formulations and gel formulations can increase the residence of drugs on the ocular surface. In case of concurrent iridocyclitis, 1% atropine eye solution can be added to dilate the pupil and reduce the iris inflammatory reaction. (2) For fungal keratitis, current medications include 0.15% dicloxacillin and 5% natamycin in drops every 1/2-1h to increase the concentration of the drug in the focal area, with antifungal eye ointment at night, and the number of doses can be reduced after the infection is controlled. In case of concurrent iridocyclitis, 1% atropine eye solution can be added to dilate the pupil and corticosteroid eye solution is prohibited. (3) for herpes simplex virus keratitis, commonly used drugs are acyclic guanosine, cyclic cytidine, triazolyl nucleoside, ganciclovir, etc., respectively, eye solution and ophthalmic ointment formulations, the acute phase every 1-2 hours dotted eye, evening antiviral ophthalmic ointment, epithelial type of the pathogenesis of the control of the disease is due to the activation of the virus in the epithelial cells replication, and therefore must be given effective antiviral drugs to inhibit the viability of the virus, careful use of Hormones; stromal keratitis is based on the immune inflammatory response of the body, so out of antiviral, anti-inflammatory treatment is more important, generally clinical antiviral treatment along with hormone therapy, but some scholars believe that immunocompetent people, usually have self-limiting, the use of hormones increases the bacterial / viral superinfection, corneal lysis, glaucoma and other serious complications. The treatment of endothelial keratitis should be accompanied by antiviral and anti-inflammatory therapy, as well as active therapeutic measures to protect the corneal endothelium. Neurotrophic keratopathy is mostly seen in the recovery phase, and treatment includes the use of preservative-free artificial tears to protect the ocular surface from moistening, and antibiotic drops and ointment to prevent infection.