The present invention relates to a wet dust collector having a circular spray nozzle for spraying air and water and capable of adjusting the cross section area of the nozzle channel of the spray nozzle. The wet dust collector according to the present invention comprises a case (100) forming an appearance; an inhaling fan (110) arranged at one side of the case (100) and generating a inhaling force for generating the flow of fluid in the case (100); a supply pipe (120) for guiding air being introduced into the case (100) by the inhaling fan (110); a spray nozzle (130) arranged at one end of the supply pipe (120) to spray a mixture; and a guiding piece (140) arranged at one side of the case (100) to guide the mixture sprayed from the spray nozzle (130) to collide and generate a whirlpool. The spray nozzle (130) is circularly formed to spray the mixture in all directions into the case (100). Therefore, the present invention improves the performance of filtering foreign materials and dust included in polluted air.
