The　single-flank　testing　of　gears　(STG),　for　its　abundant　information,　high　efficiency　and　similarity　to　actual　gear　working　conditions,　is　widely　employed　to　inspect　medium　size　gears.　Since　classical　STG　technology　is　based　on　unilateral　drive,　the　friction　and　inertia　of　a　single-flank　measuring　machine　lead　to　bigger　deformation　and　deflection　of　a　fine-pitch　gear　than　the　deviation　of　itself.　Therefore,　it　has　not　been　applied　to　fine-pitch　gears　inspection　because　of　the　limitations　of　fine-pitch　gears　in　geometric　and　mechanical　performances.　In　fact,　STG　for　fine-pitch　gears　is　one　of　the　most　difficult　problems　in　the　field　of　the　gear　metrology.　A　novel　method　of　STG　for　fine-pitch　gears　based　on　bilateral　driven　is　proposed　and　a　measuring　machine　is　developed.　Two　motors　are　employed　respectively　to　drive　two　small　gears　in　contact　and　special　techniques　are　adopted　to　avoid　interference　of　the　two　gears.　Key　techniques　related　to　the　new　measuring　machine,　such　as　the　configuration　design,　dual-motor　synchronous　drive　control,　micro-relative-angle　measurement　and　signal　wireless　transmission,　etc,　are　introduced　and　the　practical　measurement　results　are　presented.