The utility model discloses a novel boiler is ammonia water mixer for denitration adopts the theory of " the circle of contact " to design, promptly according to the size of boiler, and crude nitrogen oxide emission, local correlation index such as environmental protection requirement arrange the spray gun of some on the blender jar body, and the spray gun is installed according to certain angle, and high -concentration ammonia water and demineralized water spaced pass through the spray gun. Because the aqueous ammonia of high concentration and demineralized water have certain pressure and speed under pumping action separately, at the specific circle of contact of the internal formation of blender jar, the circle of contact opposite direction of adjacent layer simultaneously to it has also eliminated the problem that pressure each other pushed up to reach fine mixed effect. In addition, set up the switch on the spray gun of blender, can realize boiler varying duty denitration adjustment through the spray gun symmetry, that the partial mixing ware is closed at the interval. The utility model discloses install effectually, equipment cost is low, installation, convenient to use, and each other top problem of pressure of having solved in the blender high -concentration ammonia water and demineralized water becomes the denitration problem under the load condition with unable adaptation boiler.