To　achieve　high-precision　and　non-contact　measurement　of　outer　and　inner　surface　defects　on　hemispherical　shell,　a　optical　composite　measurement　method　was　proposed　on　the　basis　of　a　new　type　of　non-orthogonal　coordinate　measuring　machine.　It　combined　the　laser　probe＇s　point-scanning　with　the　vision　probe＇s　surface-scanning,　and　could　measure　not　only　the　coverage　and　distribution　of　the　surface　defects,　but　also　their　depth/height.　Actual　measurement　results　show　that　the　method　is　feasible,　precise　and　efficient.