A　tester　for　measuring　face　gear　transmission　error　was　developed　based　on　single-flank　rolling　principle.　The　tester　adopts　the　hybrid　configuration　of　vertical　and　horizontal　structures.　The　tester　is　mainly　composed　of　the　base,　precision　spindle,　grating　measurement　system　and　control　unit.　The　key　technical　problems　of　clamping,　positioning　and　adjustment　of　the　orthogonal　and　offset　gear　pairs　are　solved.　The　high-frequency　clock　pulse　subdivision　count　method　with　higher　measurement　resolution　is　adopted　to　acquire　the　data　of　transmission　error,　which　improves　the　measurement　accuracy.　The　test　and　control　software　for　face　gear　transmission　error　is　developed;　and　the　tester　can　inspect　and　measure　the　following　errors,　such　as　transmission　error　of　the　gear　pair,　the　tangential　composite　deviations　of　the　face　gear,　the　pitch　deviation,　the　eccentricity　error,　and　etc.　The　tester　also　has　the　gear　error　analysis　function,　and　meets　the　quality　inspection　requirements　for　the　face　gears　with　the　accuracy　of　grade　5.