The utility model discloses an internal air exchanger for an automobile. The internal air exchanger for an automobile comprises a motor, wherein both ends of the motor are respectively provided with an output shaft; each of the output shafts is provided with an impeller; the periphery of each of the impellers is provided with a cover casing; the inner end of each of the cover casings is hermetically connected with the casing of the motor; the outer end is provided with an air inlet which is connected with an air inlet pipe; each of the cover casings is provided with an air outlet in the direction vertical with the output shafts of the motor; each of the air outlets is connected with an air outlet pipe. After the structures are adopted, the internal air exchanger for an automobile is installed on the rear part of a steering room, the air outlets extend out of the automobile and a control button of the motor is positioned on a control panel in the automobile. A rider can starts the motor at any time according to requirements to exchange air in the automobile. Thus, dirty air in the automobile is discharged out, and fresh air is replaced in, which keeps the air in the automobile fresh. When the internal air exchanger for an automobile is used in rainy days or in winter, steam on a windscreen can be cleared away, which ensures driving safety.