The fixed cone valve has a fixed cone, and the design of the fixed cone body conforms to the characteristics of fluid mechanics. The fixed cone is supported by blades. Due to the guiding effect of the cone, when the water is discharged, it will diffuse at a wide cone angle and decompose into a thin spray shape. At this time, the water flow and the air will rub and atomize in a large area, resulting in excellent energy dissipation effect. In the fixed conical valve installed with the deflector, water is ejected from each spray hole and collides with each other. The impact of water column on each other will make the velocity energy basically disappear. It greatly reduces the impact of drainage and waterproof flow on downstream pipelines, rivers and buildings.