The utility model discloses an environmental protection balanced draft boiler, including the boiler body who is equipped with the burning chamber, the burning is equipped with the extraction opening on the chamber, is equipped with air extraction equipment on the extraction opening, and the burning intracavity is equipped with the burning platform, still includes the return -air duct, and the entry of return -air duct is established in air extraction equipment's inboard, and the export of return -air duct is equipped with the side at the burning platform, is equipped with blast apparatus in the return -air duct. As balanced draft boiler, the pressure of negative pressure is utilized to the entering mode of air, so the extraction opening exhaust is a waste gas, near burning platform can be drawn back with waste gas to the return -air duct, lets waste gas participate in the burning, and the oxynitrides of interior utensil, these oxynitrides will be once more carry out the deoxidation reaction at the burning intracavity as oxidant and fuel, and in the whole life becomes nitrogen gas, has realized reduction harmful gas's emission. And waste gas has the effect of falling oxygen, can reduce the violent degree of the burning of fuel, and the core temperature of fuel just can reduce this production that also is favorable to restraining oxynitrides like this. The utility model is used for the boiler.