The invention relates to an air sterilizing device, which comprises a steam barrel, a barrel frame, an air coil, an air inlet pipe, an air outlet pipe, a steam inlet pipe and a steam outlet pipe, wherein the air coil is arranged in the steam barrel, and extends along the height direction of the steam barrel; the air inlet pipe and the air outlet pipe are communicated with the lower end part and the upper end part of the air coil respectively; the steam inlet pipe is connected to the lower side part of the steam barrel, and is used for feeding steam; and the steam outlet pipe is connected to the upper side part of the steam barrel, and is used for exhausting steam. According to the air sterilizing device disclosed by the invention, sterilization is realized under the action of high-temperature steam in the steam barrel in the process that air flows upwards from the air inlet pipe through the coil, and a good sterilizing effect is achieved; and moreover, the air sterilizing device is simple in structure, and is low.