The utility model relates to an air preheater for the thermal recycle of heating furnace flue gas. This pre -heater includes the box, sets up the baffle in the box, two districts about the baffle is divided into in with the box, and upper flue gas flows out the district and flows into the district with the lower floor flue gas, lets in the air in the heat exchange tube, realizes the heat transfer between upper strata and lower floor's flue gas and the air respectively, and the distribution has the baffling board on box and the baffle in upper flue gas flows out the district, has air inlet and export at the upper and lower parts of whole box, has flue gas inlet and export on the left of the box, has U type connecting pipe on the box right side. The air preheater that this application provided has simple structure, and heat exchange efficiency is high, and the energy has been practiced thrift to the heat can the make full use of flue gas smugglied secretly.