The invention relates to the technical field of an epoxy resin powder coating, and more specifically relates to a strong-weatherability epoxy resin powder coating and a preparation method thereof. Thestrong-weatherability epoxy resin powder coating is prepared by epoxy resin, a curing agent, hydroxyl silicone oil, a silane coupling agent, salicylic acid, an acetone aqueous solution, polyvinylidene fluoride, polyvinyl fluoride or polytetrafluoroethylene, an ABS resin monomer composition, an initiator, water, an inorganic mineral filler, a levelling agent and an UV absorbent. The epoxy resin ismixed with hydroxyl silicone oil and the silane coupling agent to form organosilicon modified epoxy resin, the organosilicon modified epoxy resin is mixed with a mixture of polyvinylidene fluoride, polyvinyl fluoride or polytetrafluoroethylene, and the ABS resin monomer composition, and extrusion moulding is carried out to obtain the epoxy resin powder coating, the epoxy resin participates in anorganic silicone resin system, the material and the ABS resin composition form a high-molecular polymerization structure through polyvinylidene fluoride for further modification, and the strong-weatherability epoxy resin powder coating has the advantages of damp heat resistance, corrosion resistance, strong weatherability, good mechanical property, convenient preparation, concise process, and safety and non toxicity.