The invention provides a powder fire-retardant coating containing bromine carbon polyester and preparation method thereof, comprising( by weight percentage): end-carboxyl bromine carbon polyester resin 55.0-70.0%, curing agent 5.5-7.0%, dicyandiamide 0.3-0.5%, solid flow agent 1.5-2.0%, liquid flow agent 0.5-1.0%, epoxy resin 4.5-9%, white titanium pigment 5.0-20.0%, precipitated barium sulfate 2.0-15.0%, zinc oxide 2.0-15.0%, light calcium carbonate 0-5.0%, zinc acetate 0.3-0.5%, antimony oxide 0.2-0.5%, molybdenum hemitrioxide 0.2-1.0% and zinc borate. The preparation method thereof comprises: mixing the liquid flow agent and epoxy resin; mixing the end-carboxyl bromine carbon polyester resin, solid flow agent and liquid flow agent; adding curing agent, dicyandiamide, white titanium pigment, precipitated barium sulfate, zinc oxide, light calcium carbonate, zinc acetate, antimony oxide, molybdenum hemitrioxide and zinc borate; fusing and extruding the mixture using an extruder; tabletting, crushing, whirlwind separating and screening to obtain the coating.