Herpes zoster is a viral skin disease caused by varicella-herpes virus, and treatment is mainly antiviral. As a first-line antiviral drug, acyclovir is mainly used internally and externally. For the internal treatment of herpes zoster, the adult dosage of acyclovir is usually 0.8g, 5 times a day, while the elderly, pregnant women and children should be cautious in applying acyclovir. Topical acyclovir is mainly available as ointment, eye drops and water, which can be applied topically twice a day depending on the rash; eye drops are mainly for herpes zoster in the eye, 3-5 times a day to relieve pain and shorten the course of the disease. Acyclovir can also be applied in combination with other drugs.