The utility model discloses a reduce uneven device of air heater hot junction inflation, including air heater and controller, a plurality of sides of air heater's flue gas inlet are connected through a plurality of connecting pipes to air heater's exhanst gas outlet, just a plurality of sides of air heater's flue gas inlet all are equipped with temperature sensor, are equipped with flow control system on every connecting pipe, the flue gas temperature signal that the temperature sensor of every side of air heater's flue gas inlet will incline most likely all transmits to the controller, air heater's flue gas inlet's high temperature side and low temperature side are distinguished according to temperature signal to the controller, simultaneously, flow control system is adjusted according to the temperature difference of flue gas inlet high temperature side with the flue gas inlet low temperature side to the controller to the low temperature flue gas of control air heater's exhanst gas outlet gets into the air input of air heater's flue gas inlet high temperature side. Can reduce air preheater entry high temperature side gas temperature.