The invention discloses an aerosol inhalation device used in the paediatric internal medicine. An aerosol transfer chamber is used for separating the mouth of a sick child and an aerosol machine; gas expired by the sick child enters a disinfection device from an exit pipe at the lower part of the aerosol transfer chamber for disinfection and then is discharged, so as to prevent cross infection during use; a hose is used, and thus the use is free and flexible; a nipple-like inspiratory nozzle is designed, so that the sick child can suck the nipple-like inspiratory nozzle, and the fear of the sick child in treatment can be reduced; a fog amount adjusting button is adopted, thus the amount of fog can be regulated according to the different requirements of the sick child, the requirements of different sick children are effectively met, and the work difficulty of medical workers is reduced. According to the aerosol inhalation device, aerosol treatment and oxygen treatment can be performed simultaneously by means of a support pipe, a biting nozzle, the adjusting button, activated carbon fiber, a hollowed-out ventilation fixed piece and a flexible piece, deep filtering of waste gas is facilitated, the cross infection is prevented, the fog amount can be controlled, tracheal spasm and difficult breathing are prevented, the use is further facilitated, and the service life is prolonged.