The invention relates to a combined device of a circular water distributor and a defogger, which belongs to the technical field of utilizing gas-liquid contact to purify waste gas in a boiler. The combined device comprises the water distributor and the defogger, wherein the water distributor is provided with a main pipe, a plurality of manifold branches, branching pipes, water inlets and a plurality of spray heads; the main pipe is circular, opposite sides of the main pipe are provided with one water inlet respectively, the manifold branches are communicated to two sides of the main pipe, wherein two ends of the manifold branches positioned in the center of the circular main pipe are communicated with the corresponding main pipe, the branching pipes are arranged between the manifold branches, and two ends of the branching pipes are communicated with adjacent manifold branches; the manifold branches and the branching pipes are downwards provided with the plurality of spray heads, and sprayed water fog can completely cover the cross section of the inside of an absorbing tower; reinforcing ribs are fixedly connected with the upper parts of the manifold branches; an inverted T-shaped fixed mount is arranged above the reinforced ribs; and the defogger is arranged on the inverted T-shaped fixed mount. The inverted T-shaped fixed mount consists of two groups of corniform sections back to back. The combined device is used for spraying water by counter current and defogging in the absorbing tower.