The　additive　manufactured　(AM)　parts　of　aluminum　alloys　have　been　widely　used　in　defense,　aerospace,　automotive　and　other　industries.　There　is　a　growing　demand　for　joining　or　repairing　of　the　AM　parts　of　aluminum　alloys　using　welding　technology.　However,　the　problems　of　high　porosity　and　joint　softening　are　occurred　when　welding　of　aluminum　alloy　AM　parts,　which　have　become　technical　bottlenecks　that　need　to　be　solved　urgently.　Laser　welding　of　AlSi10Mg　alloys　fabricated　by　selective　laser　melting　(SLM)　with　an　addition　of　Er　and　Zr　in　the　filler　metal　was　carried　out.　The　effect　of　Er　and　Zr　addition　on　the　porosity,　microstructures　and　mechanical　properties　of　the　welded　joints　was　investigated,　and　the　contribute　of　Er　and　Zr　addition　to　the　yield　strength　(YS)　of　the　welded　joints　was　calculated.　Compared　that　joints　without　Er　and　Zr　addition,　the　average　ultimate　tensile　strength　(UTS)　and　YS　of　the　welded　joints　with　Er　and　Zr　addition　have　been　increased　by　10.5%　and　23.5%,　respectively.　The　improved　mechanical　poverty　of　the　welded　joints　is　due　to　the　refined　alpha-Al　grains　and　Si-rich　cellular　networks,　and　the　reduced　hydrogen　pores　occurred　in　the　weld　metal　(WM)　with　the　addition　of　Er　and　Zr.　The　YS　calculation　of　the　weld　joints　indicates　the　most　important　contribution　to　the　YS　is　the　enhancement　effect　of　the　Si-rich　networks　with　Er　and　Zr.