The utility model provides a sweep car futilely with defogging presses down dirt function sweeps vehicle, vehicle box body and the device of sweeping the floor including the sanitation futilely, and the vehicle box body bottom sets up the dust collecting chamber, the device of sweeping the floor feeds through dust collecting chamber top gravitational dust collection's one -level clean room throughthe wind channel I of induced drafting, after removing dust, the one -level clean room feeds through the second grade clean room that its middle part space whirlwind centrifugation was removed dust,it makes things convenient for the clear defogging chamber of dismouting to communicate to be equipped with from top to bottom with the second grade clean room, and defogging chamber is through II subassembly of straining that feed through the three -stage dust -removal rooms again through oblique decurrent wind channel III of top horizontal air channel, strain the horizontal rear of subassembly installation fan, the fan still has the ventilation duct V who sets up the clean air after outside discharge is filtered in induced draft wind channel VI and the slant. The utility model discloses thedifficult dirt that produces, and is easy to maintain. Remove dust thoroughly, the present invention has simple and compact structure. Reasonable layout. The operation is high -efficient, low cost. Safety and reliability. The air is the moisture -bearing not, economical and practical, generally be used for the road to clean the aspect, utensil market spreading value.