A flue gas purifying collector and process method thereof are provided. The flue gas purifying collector comprises a transpiration cooling flue, a water seal, a flue, a ring-seal Venturi tube, a dehydrator, a flowmeter, pipelines, a main air blower, a three-way valve, a rotary water seal, an irradiation flue pipe, a water treatment device, a U-shape water seal, a gas cabinet, etc, characterized in that the transpiration cooling flue is connected with a cooling washing tower with a nozzle arranged inside the cooling washing tower, the flue gas outlet on the lower part of the collector is connected to the flue gas inlet on the lower part of the ring-seal Venturi tube, the flue gas outlet of the ring-seal Venturi tube is connected to the dehydrator, and on the throat opening of the ring-seal Venturi tube and below the heavy iron are arranged a water supply pipe and a nozzle, and a heavy iron inversed cone is arrange inside the throat opening. An up-running type flue gas flowing manner and water supply below the heavy iron are employed in the process provided in the invention, redundant mechanical water can be directly reclaimed without passing through the throat opening of the ring-seal Venturi tube, water is atomized thoroughly and agglomerates with dust on the throat opening of the ring-seal Venturi tube, thereby improving dust purifying and dust collecting effect, facilitating the adjustment of the heavy iron, and preventing dust agglomeration below the heavy iron and dust deposit on the throat opening of the ring-seal Venturi tube.