Different　weld　shapes　of　45mm　thickness　TA15　titanium　alloy　were　obtained　by　choosing　appropriate　electron　beam　welding　parameters,　and　the　influence　of　weld　shape　on　fatigue　performance　of　the　joints　was　investigated　by　analytic　hierarchy　process.　The　results　show　that　four　typical　weld　shapes　were　formed,　according　to　their　geometry　characters,　which　are　respectively　named　as　bell　shape,　funnel　shape,　nail　shape,　and　wedge　shape.　Weld　shape　effect　the　fatigue　life　and　dispersion　of　the　experiment　data　of　the　joint.　The　sequencing　of　fatigue　performance　of　the　joints　with　four　different　shapes　by　analytic　hierarchy　mathematical　model　is　bell　shape,　funnel　shape,　wedge　shape,　and　nail　shape.　It　is　validated　by　trial　results　that　the　analytic　hierarchy　mathematical　model　is　effective　and　practical.