A gas scrubber that generates no plumes and a gas scrubbing method are disclosed. The disclosed gas scrubber includes: a housing, a gas-liquid contacting unit arranged inside the housing and configured to scrub process gas by contacting the process gas with a washing liquid, wherein the gas-liquid contacting unit includes a wet unit and a dry unit, a part of the process gas passes through the wet unit along with the washing liquid and the rest of the process gas passes through the dry unit, a washing liquid-distributing unit for spraying the washing liquid into the gas-liquid contacting unit, a gas mixing unit for mixing a first exhaust gas with a second exhaust gas without generating plumes, wherein the first exhaust gas is discharged from the wet unit and the second exhaust gas is discharged from the dry unit, and an exhausting means arranged inside or outside the housing.