Gears　are　core　components　of　transmission　systems.　The　current　trend　of　gear　measurements　is　the　rapid　and　full　digitization.　To　rapidly　obtain　information　on　the　three-dimensional　(3D)　shape　of　the　gear　tooth　flank,　a　3D　point　cloud　measurement　system　based　on　a　line　structure　light　sensor　and　high　precision　air　floating　rotary　table　is　proposed.　The　system　can　acquire　more　than　1.5　million　3D　data　points　on　one　side　of　the　gear　tooth　flank　within　less　than　5　s.　In　this　study,　the　measured　3D　point　cloud　data　is　used　to　calculate　the　profile　error,　pitch　error,　then　compared　to　those　obtained　from　traditional　contact　measurements.　In　addition,　tooth　flank　error　was　evaluated.　The　results　show　that　the　3D　point　cloud　measurement　system　can　perform　fast　and　accurately　in　3D　measurements　of　gears　and　it　is　a　novel　system　for　gear　measurement　and　error　calculation.