The invention relates to a concrete structure of an environment-friendly downward-suction-type range hood. A coil is arranged in a cladding cavity and communicates with a water tank, thus the water surface in the coil is flush with the water tank so as to keep enough water in the coil, and thus dry burning is prevented; then the water in the coil can be heated while cookware is heated through an oven hole, when the water in the coil is boiled, steam is generated, enters a steam exhaust pipeline from a steam exhaust opening of the coil and then enters a flue, and thus lampblack entering the flue from a lampblack guiding hole can be subjected to steam atomization; the atomized lampblack is decomposed and enters a lampblack exhaust channel under the effect of a first draught fan to make contact with a filtering net to be condensed into water droplets and drip into a recovery filtering chamber; and due to the fact that oil is lighter than the water, when the water in the recovery filteringchamber rises to an oil overflow hole, the oil flows into an oil recovery chamber through the oil overflow hole in the side wall, and polluted water is filtered into recyclable water through adsorption filter materials in the recovery filtering chamber and enters a water recovery chamber through a drainage hole.