Experimental　study　of　slab　CO2　laser　bead-on-plate　welding　and　filling　wire　welding　7075-T6　high　strength　aluminum　alloy　of　2.4　mm　thickness　has　been　completed.　The　mechanical　properties　of　welding　joints　have　been　analysed.　Through　analysis　of　influence　of　laser　power,　focal　length,　welding　velocity,　working　gas　and　shielding　gas　on　weld　shaping　and　welding　stability,　filling　wire　welding　of　7075-T6　high　strength　aluminum　alloy　is　put　forward.　On　the　basis　of　the　optimization　of　feeding　direction,　feeding　angle,　feeding　velocity　and　feeding　position,　filling　wire　welding　of　7075-T6　alloy　is　completed　successfully　with　slab　CO2　laser.　The　tensile　strength　of　as-welded　welds　with　AlSi12　is　360.8　MPa　and　with　AlMg4.5MnZr　414.6　MPa.　The　tensile　strengths　of　welds　after　heat　treatment　are　404.2　MPa　(75　percents　of　base-metal)　and　482.6　MPa　(88　percents　of　base-metal)　for　AlSi12　and　AlMg4.5MnZr,　respectively.