The invention discloses a preparation method of a fluorocarbon coating. The fluorocarbon coating is composed of a component A and a component B. When in use, the component A and component B are mixed in a mass ratio of (1-2):1. The component A is composed of fluorocarbon polyurethane prepolymer, a nano inorganic filler, a hydrolysis stabilizer, a dispersing agent, a leveling agent, a tin catalyst, an initiator, hydroxy acrylate and an anhydrous diluter; and the component B is composed of a hydroxy acrylic resin, an isocyanate curing agent and an anhydrous diluter. The method can effectively enhance the crosslinking density of the polymers in the fluorocarbon coating, so that the fluorocarbon coating has more compact IPN (interpenetrating network) structure. The prepared fluorocarbon coating has the advantages of excellent weather resistance, excellent water resistance, excellent chemical resistance, excellent salt spray resistance, outstanding hardness and outstanding abrasion resistance, and is a high-performance fluorocarbon coating applicable to solar cell back panels.