The invention discloses a fresh air ventilator. The fresh air ventilator comprises a right side plate, a left side plate, a bottom plate, a back plate, a door sheet assembly, a right inner side plateassembly, a left lower inner side plate assembly, a left middle inner side plate assembly, a silencing mesh plate, a top filtration supporting seat, a fan mounting plate assembly, a heating mesh frame, a middle cross beam, a control panel box assembly, an air volume meter supporting column, a Shengjiu hinge, a door pull rod, a middle cover plate, a hanging frame, a top plate assembly and a lower wind shield, the right side plate and the left side plate are fixed on the corresponding two sides of the bottom of the bottom plate through bolts correspondingly, the back plate is fixed on one side of the right side plate and one side of the left side plate through bolts, the top plate assembly is fixed at the bottom of the right side plate, the bottom of the left side plate and the bottom of theback plate through bolts, one side of the right side plate is connected with the door sheet assembly through the Shengjiu hinge, the door sheet assembly is connected with the top plate assembly through the door pull rod. According to the fresh air ventilator, the sound insulation performance is good, the service life of the fan is prolonged, and the indoor environment sanitation and the body health of people can be protected.