5083　aluminum　alloy　is　widely　used　in　shipbuilding　and　high　speed　train　manufacturing　industry.　The　main　problems,　such　as　sag　and　undercut,　occur　during　fiber　laser　welding　of　5083　aluminum　alloy.　To　overcome　these　problems,　5083　aluminum　alloy　with　the　thickness　of　4　mm　is　welded　using　5087　filler　wire　in　our　present　work.　The　effects　of　welding　parameters　on　the　weld　forming　are　studied　in　details.　And　the　microstructure　and　mechanical　properties　of　joints　are　also　investigated.　The　result　shows　that　fiber　laser　welding　with　filler　wire　can　effectively　avoid　the　weld　surface　depression　and　undercut　defects　by　choosing　suitable　processing　parameters　as　power　of　6　kW,　welding　speed　of　7.5　m/min,　wire　feed　rate　of　4.5　m/min,　distance　between　laser　and　wire　of　1.0　mm,　and　also　gets　a　good　joint　forming　with　fine　grain　weld.　The　average　tensile　strength　of　the　joint　with　filler　wire　is　304　MPa,　about　88%　of　the　parent　material,　which　is　also　about　6.17%　higher　than　that　of　the　autogenous　weld.　The　average　elongation　of　5.43　%　with　filler　wire　is　found,　which　increases　by　52%　than　that　of　the　autogenous　joint.　After　the　transverse　tensile　test,　the　joint　with　filler　wire　is　fractured　along　the　weld,　which　shows　the　ductile　characteristics.