In　this　paper,　hydrophilicity　after　nanosecond　pulsed　laser　cleaning　of　lubricating　oil　on　the　surface　of　DC04　steel　was　investigated.　Influencing　parameters　of　temperature　field　distribution　and　ablation　depth　on　laser　cleaned　steel　surface　were　simulated　by　using　COMSOL　Multiphysics　software;　The　results　show　that　when　the　average　laser　power　is　50　W,　the　ablation　depth　of　the　steel　surface　gradually　increases　with　the　decrease　of　the　laser　scanning　speed,　and　the　increase　of　the　ablation　depth　leads　to　the　decrease　of　the　contact　angle　of　the　steel　surface.　Subsequently,　an　experimental　study　of　nanosecond　pulsed　laser　cleaning　of　DC04　steel　surfaces　was　carried　out.　The　results　show　that　the　contact　angle　of　the　steel　surface　shows　a　tendency　of　decreasing　and　then　increasing　with　the　increase　of　the　laser　scanning　speed.　When　the　average　laser　power　was　50W,　the　scanning　pitch　was　0.03mm　and　the　scanning　speed　was　500mm/s,　the　lubricant　on　the　steel　surface　was　cleaned　and　had　the　best　hydrophilicity　on　the　surface.　The　static　contact　angle　of　the　steel　surface　changed　from　the　original　84°　to　18°.　©　2023　SPIE　·　0277-786X　·