The invention discloses polytetrafluoroethylene modified epoxy resin powder paint. Raw materials of the paint include: epoxy resin, modified polytetrafluoroethylene, organic silicon resin, phenolic resin, tetramethylthiourea, polyethylene wax, glycerol, nano-zinc oxide, fumed silica, attapulgite, talcum powder, titanium dioxide, 2-phenylimidazole, toluene diisocynate and flatting agents. The modified polytetrafluoroethylene is prepared according to the following process: polytetrafluoroethylene ultrafine powder is placed in a 60 Co radioactive source for pre-irradiation under an aerobic condition and taken out after the absorbed dose is between 35 kGy and 45 kGy; next, styrene, vinyl triethoxy silane, 4-vinylpyridine and absolute methanol are added, and the mixture is subjected to ultrasonic oscillation and then temperature rise reaction under the protection of nitrogen; after reaction is over, washing and drying are performed to obtain the modified polytetrafluoroethylene. The polytetrafluoroethylene modified epoxy resin powder paint is good in weather fastness and ageing resistance, excellent in water resistance and corrosion resistance, good in decorative performance and long in service life.