The　6106-T6　aluminum　alloy　hollow　extrusion　profiles　having　a　lock　bottom　structure　were　welded　via　fiber　laser-cold　metal　transfer　(CMT)　arc　hybrid　welding,　fiber　laser-variable　polarity　tungsten　inert　gas　(VPTIG)　hybird　welding,　and　fiber　laser-melt　inert　gas　(MIG)　hybrid　welding.　Subsequently,　a　hybrid　welding　joint　with　good　forming　properties　and　without　clear　defects　was　obtained　using　optimized　welding　parameters.　Furthermore,　the　joint　microstructure,　tensile,　and　fatigue　properties　were　studied,　and　the　fatigue　fracture　mechanism　and　fracture　morphology　were　analyzed.　The　results　denote　that　the　sizes　of　equiaxed　grains　at　the　center　of　the　laser-CMT　and　laser-VPTIG　hybrid　welding　joints　gradually　decrease　from　the　upper　part　of　the　bead　to　the　bottom.　However,　the　sizes　of　the　coarse　equiaxed　grains　in　the　upper　and　lower　parts　do　not　change　considerably,　and　the　sizes　of　grains　at　the　center　of　the　laser-MIG　hybrid　welding　joint　are　large.　Furthermore,　the　tensile　strengths　of　the　laser-CMT,　laser-VPTIG,　and　laser-MIG　hybrid　welded　joints　are　213.0,　198.0,　and　200.0　MPa,　respectively.　These　values　denote　a　certain　degree　of　strength　loss　when　compared　with　that　of　the　base　metal.　The　fatigue　limits　of　the　three　hybrid　welded　joints　are　105.00,　100.83,　and　113.50　MPa,　respectively.　All　the　fatigue　fracture　positions　are　located　in　the　columnar　crystal　zone　at　the　fusion　line　of　the　welding　joints.　In　addition,　the　fractures　are　dimpled,　indicating　a　typical　ductile　fracture.　©　2019,　Chinese　Lasers　Press.　All　right　reserved.