The invention discloses an internal powder spraying process for petroleum tubes. The internal powder spraying process includes the flowing steps: 1, using a hot cleaning furnace to incinerate various grease dirt and impurities on the inner surfaces of the tubes; 2, performing surface sand blasting on the inner walls of the tubes; 3, utilizing high-pressure airless spraying equipment to spray undercoats onto the petroleum tubes; 4, putting the tubes into a continuous furnace for firing, and enabling the temperatures of tube bodies to reach 180 DEG C-200 DEG C; 5, when the surface temperatures of the tubes are higher than 170 DEG C, using powder spraying equipment to perform internal powder spraying on the petroleum tubes; 6, after powder spraying is finished, immediately putting the tubes into a curing furnace for firing for 60 minutes at the curing temperature of 220 DEG C-235 DEG C; 7, performing leaking point inspection after the tubes are cooled, wherein the leaking point of a qualified product is zero. A solvent coating spraying process is replaced by the environment-friendly powder spraying process, so that requirements of oilfields on internal coatings of the petroleum tubes are met, application ranges of the tubes are further expanded, and good social and economic benefits are realized.