Gray nail refers to onychomycosis. The medicines suitable for the treatment of nail fungus include compound povidone-iodine applicator, amorolfine hydrochloride applicator and so on. 1. Compound Povidone Iodine Apply: It should be noted that this drug can not be shared with sodium thiosulfate, mercury bromide, and those who are allergic to iodine can not use it. Pregnant and lactating women are prohibited. This drug is for external use and should not be taken orally. 2. Amorolfine Hydrochloride Application: It should be noted that it is forbidden for those who are allergic to this drug. It is contraindicated for pregnant women, lactating women and children. Avoid contact with eyes and other mucous membrane areas. This drug can only be used externally and should not be taken orally. If irritation or allergic reaction occurs with the use of the drug bureau, immediately stop the drug, and clean the local area, if necessary, consult a physician. Generally speaking, with onychomycosis, it is also necessary to combine oral medication, such as itraconazole capsules, terbinafine tablets, the effect is better. If found suffering from nail fungus, it is recommended to go to the hospital in time under the guidance of the doctor standardized treatment. Drugs need to be used in accordance with medical advice.