The invention relates to an aerosol virtual impacting concentration separator which is characterized in that the separator comprises an outer drum; one side of the lower part of the outer drum is provided with an exhaust port and an exhaust fan which is connected with the exhaust end of the exhaust port; the outer drum is internally provided with three stages of separation inlet components from top to bottom; the first stage component comprises an aerosol air intake, the front end of the first stage component is provided with a waterproof and inset resistant net cover, the first stage component is internally provided with a flow limit column and a ring gap is arranged between the flow limit column and the first stage component; the second stage component comprises a large particle collection port and a second stage separation intake board, the large particle collection port is correspondingly arranged under the aerosol air intake and a plurality of second stage spouts are cut evenly at the periphery of the second stage separation intake board; the third stage component comprises a tank which is connected under the second stage separation intake board, the third stage spouts are cut at the bottom of the tank and a third stage collection port is arranged under the third stage spouts. By utilizing the flying inertia of aerosol particle and adopting the virtual impacting principle, the separator of the invention separates the respirable particle with the diameter of 2 microns to 12 microns, which contains microorganism, from great air flow and concentrates the respirable particle to comparatively small air flow.