The invention discloses an electrolysis electrode loaded with graphene modified tin dioxide and a preparation method thereof. The electrolysis electrode consists of a titanium substrate and the graphene modified tin dioxide loaded on the titanium substrate, wherein each square centimeter of titanium substrate is loaded with 0.1 to 4mu g of graphene modified tin dioxide; and a mass ratio of graphene to tin dioxide is (0.1-2.5):1,000. The preparation method comprises the following steps of: pretreating the titanium substrate; preparing graphene-tin tetrachloride sol; vertically immersing the pretreated titanium substrate in the graphene-tin tetrachloride sol for impregnation, airing, drying, and roasting; and impregnating and roasting for three to five times, and cooling with a furnace to obtain the electrolysis electrode loaded with the graphene modified tin dioxide. The preparation method is simple, and easy to popularize and apply, the high property of the graphene is furthest protected, the catalysis efficiency of the electrolysis electrode is maximally improved, and the prepared electrolysis electrode has high electro-catalysis efficiency and stable property and is reusable.