The utility model discloses a can prevent portable flying dust sampling device of flue gas dewfall, hydrostatic measuring point, heat preservation casing, flying dust storage jar, separator and fixing base inside and outside air ejector, sampling gun are emanated to flying dust sampling gun, flue gas suction tube, flue pipe wall, the first air ejector of emanating, second, the utility model discloses a mode that increases flue gas insulation sandwich realizes the heat preservation of flue gas, prevents that the vapor condensation from stopping up the sample passageway, and the problem that the route was stopped up in the vapor condensation can fine solution be got in the grey route to this device, and it need not applied power source, convenient and practical to gather materials on the spot in addition.