A mixer is only provided with an exhaust gas and hot-blast air dual-medium powder feeding system having an exhaust gas tube and a hot-blast tube. The invention relates to a powder feeding system and belongs to the technical field of coal-fired boilers. The powder feeding system solves the problems of bad mixing effect of the exhaust gas and hot-blast air and so on in the exhaust gas and hot-blast air dual-medium powder feeding system because the exhaust gas and hot-blast air mixer adopts a structure form that a plurality of exhaust gas nozzles are centralized in one air distribution main pipe. The powder feeding system includes a wind powder mixer, an exhaust gas bellows, a hot-blast pipeline, a primary air pipeline, a primary air powder feeding pipeline, an exhaust gas pipeline and an exhaust gas and hot-blast mixer. The exhaust gas and hot-blast mixer is composed of the exhaust gas nozzle, the hot-blast tube, a mixing tube and a closed hot-blast receiving chamber. One end of the exhaust nozzle is inserted in the closed hot-blast receiving chamber. The mixing tube and the exhaust nozzle are coaxially and oppositely arranged and one end of the mixing tube is communicated with the closed hot-blast receiving chamber. One end of the hot-blast tube is communicated with the closed hot-blast receiving chamber. The invention is mainly applicable for powder feeding of pulverized coal boiler for power plants.