The invention relates to a silver electrode surface cleaning protective agent and a preparing method thereof. The silver electrode surface cleaning protective agent comprises, by weight, 35-55 parts of vegetable oil, 4-6 parts of propylgallate, 0.4-3 parts of a parabens corrosion remover, 70-100 parts of an emulgator, 35-45 parts of vitamin C, 10-20 parts of persimmon tannin and 150-200 parts of water. The silver electrode surface cleaning protective agent is obvious in silver electrode surface oxide removing effect, electrodes are not damaged, the antioxidant effect is obvious, and the silver electrode surface oxidizing rate can be effectively delayed.