Infrared　thermography　has　become　increasingly　important　for　non-destructive　testing　to　detect　internal　defections,　involving　delaminations,　cracks　and　voids.　In　this　paper,　the　principle　of　infrared　thermography　is　presented　briefly.　And　a　finite　element　approach　is　proposed　to　simulate　the　process　of　infrared　thermography　nondestructive　testing　about　QFN　packages.　By　changing　with　the　length　and　the　thickness　of　the　delamination　and　the　size　of　uniform　surface　heat　flux,　the　surface　thermal　characteristics　of　a　QFN　are　analyzed.　The　simulation　results　can　provide　basis　and　reference　for　the　following　work　to　detect　defects　in　packages　by　infrared　thermography　method.