Gears　are　important　mechanical　parts　that　transmit　motion　and　power　by　interaction　of　meshed　tooth　surfaces.　The　processing　quality　of　tooth　surfaces　has　a　direct　influence　on　the　performance　of　gear　transmission.　In　order　to　verify　whether　the　machining　accuracy　of　the　gear　tooth　surface　meets　the　design　and　use　requirements,　it　is　necessary　to　measure　its　accuracy　with　related　instruments.　The　geometric　characteristics　of　the　gear　tooth　surface　include　tooth　profile,　helix,　tooth　pitch　and　surface　roughness,　etc.　For　the　measurement　of　tooth　profile,　commonly　used　instruments　can　not　obtain　the　values　of　tooth　profile　shape,　waviness,　and　surface　roughness　in　one　measurement.　The　cylindrical　gear　tooth　profile　measurement　scheme　based　on　the　roughness　profiler　can　realize　the　simultaneous　measurement　of　tooth　profile　deviation,　waviness　and　surface　roughness.　This　is　a　relatively　novel　method,　and　there　is　a　lack　of　relevant　study　on　the　uncertainty　evaluation　of　the　measurement　results.　This　article　introduces　the　measurement　principle　of　cylindrical　gear　tooth　profile　based　on　roughness　profiler,　and　analyzes　the　source　of　uncertainty　in　the　measurement.　The　feasibility　of　the　method　is　verified　through　experiments,　and　the　uncertainty　evaluation　result　is　given.