Conjunctivitis is the most common ocular surface disease in ophthalmology. It is mainly manifested as a local inflammatory reaction and treatment requires active anti-inflammatory therapy. The clinical symptoms of conjunctivitis are varied, such as foreign body sensation, burning, itching, tearing, increased secretion, etc. There is also conjunctival congestion, papillary hyperplasia, follicle formation, true and false membranes, bulbar conjunctival edema, subconjunctival hemorrhage, and even eyelid swelling, pseudohyperthalmia, enlarged preauricular lymph nodes, and if the cornea is affected, photophobia, tearing, and eye pain. The specific treatment is mainly based on the cause, according to the cause of conjunctivitis can be divided into: bacterial conjunctivitis, viral conjunctivitis, chlamydial conjunctivitis (commonly known as trachoma) bacterial conjunctivitis is mainly local application of anti-inflammatory eye drops, if the symptoms are serious, systemic application of antibiotic treatment if necessary, and at the same time do a good job of disinfection and isolation to prevent infection. Viral conjunctivitis is also mainly local application of antiviral eye drops, and if necessary, hormonal eye drops, emphasizing that hormonal eye drops should not be abused, and should be used under the guidance of an ophthalmologist, with timely follow-up, and also good disinfection and isolation to prevent infection. Chlamydial conjunctivitis is mainly local application of rifampicin, sulfonamide ophthalmic drugs, and in severe cases, systemic application of polytetracycline and erythromycin. In conclusion, conjunctivitis is very common, mainly due to inflammation, and needs to be treated differently for the cause.