The invention discloses a respiratory action self-cleaning device of a mainframe of a desk computer. The respiratory action self-cleaning device comprises a first alternative-current servo motor, wherein a first respiration opening is arranged at heat radiation holes in the back side of the mainframe of the desk computer; a second respiration opening is arranged at a heat radiation hole in the side surface of the mainframe of the desk computer; the first alternative-current servo motor drives an air compressor to generate compressed air; a second alternative-current servo motor is adopted to drive a vacuum pump through a coupling to implement a vacuum sucking function; the generated compressed air enters the mainframe of the desk computer through a pulse valve to generate pulse flow and turbulent flow; under the action of a reversing valve, the first respiration opening is in a dust blowing state or a dust sucking state, and the second respiration opening is in a dust sucking state or a dust blowing state, so that the respiration function is achieved; a central controller is used for receiving and processing signals of a photosensitive sensor. Through the adoption of the respiratory action self-cleaning device, a cleaning effect is ensured as functions of turbulent flow and the pulse flow are utilized with the combination of the internal structural characteristics of the desk computer.