The　welding　process　has　been　recently　introduced　to　join　of　the　materials　fabricated　by　powder　bed　fusion　(PBF)　additive　manufacturing　(AM)　to　meet　the　requirement　for　the　large　parts　and　their　repair　in　service.　However,　one　of　the　main　issues　is　the　high　susceptibility　to　the　hydrogen　pores　occurred　during　fusion　welding　of　the　PBF　aluminum　(Al)　alloys.　Autogenous　laser　welding　of　a　selective　laser　melting　(SLM)　AlSi10Mg　alloy　was　firstly　carried　out　in　comparison　with　the　casting　AlSi10Mg　alloy　to　examine　the　hydrogen　pore　characteristics.　Singlepass　welding　with　filler　powders　and　laser　melting　deposition　(LMD)　welding　were　then　performed　on　SLM　AlSi10Mg　alloys　to　reduce　the　hydrogen　pores.　The　porosity,　microstructure,　microhardness　and　tensile　property　of　the　welded　joints　were　investigated.　As　a　result,　a　high　susceptibility　to　hydrogen　pores　of　SLM　AlSi10Mg　alloys　is　occurred　in　the　weld　metal　(WM)　of　the　welded　joint　produced　by　autogenous　laser　welding　and　singlepass　laser　welding　due　to　the　high　hydrogen　content　pre-existing　in　the　base　metal　(BM).　However,　LMD　welding　has　been　shown　to　effectively　reduce　the　pore　size　and　the　porosity　generated　in　the　WM　of　SLM　AlSi10Mg　alloys.　The　laser　welding　of　SLM　AlSi10Mg　alloys　produces　lower　hardness　and　ultimate　tensile　strength　(UTS)　than　that　of　the　BM.　However,　the　LMD　welding　of　SLM　AlSi10Mg　alloys　achieves　higher　hardness　and　UTS　than　those　of　the　autogenous　laser　welding　and　single-pass　laser　welding,　which　is　attributed　to　the　refined　microstructures　and　the　reduced　hydrogen　pores　in　the　WM.