A　highly　effective,　environmentally　friendly,　high-power　continuous-wave　laser　(CWL)　transmitter　was　newly　developed　to　remove　corrosion　products　from　severely　corroded　steel　structures.　In　this　regard,　treatment　conditions　of　dry　laser　cleaning　(DLC)　and　wet　laser　cleaning　(WLC)　of　the　drench,　soak,　and　rinse　methods　are　adopted,　and　the　cleanliness　effect　is　compared　with　that　of　conventional　abrasive　blasting　treatment.　The　morphologies　and　chemical　compositions　of　untreated　and　treated　surfaces　are　analyzed　using　three-dimensional　digital　microscopy,　laser　confocal　microscopy,　and　scanning　electron　microscopy-energy　dispersive　X-ray　spectrometry.　The　results　show　that　laser　cleaning　can　efficiently　remove　corrosion　products　and　salts　that　severely　corrode　steel　members,　as　well　as　prolong　the　re-corrosion　time　of　the　cleaned　surfaces.　WLC　can　achieve　excellent　microscopic　cleaning　and　reduce　the　effect　of　high-temperature　inputs　on　the　surface　via　laser　irradiation.　Further　mechanistic　analysis　indicates　that　ablation,　melting,　and　evaporation　during　laser　cleaning　primarily　contribute　to　the　removal　of　corrosion　products　and　salts.　As　a　result,　the　WLC　drench　method　yields　the　best　surface　cleanliness　and　is　suitable　for　practical　engineering　applications.　This　study　provides　a　basis　for　maintaining　severely　corroded　structures　via　laser-cleaning　techniques.