An　on-line　water-meter　verification　system　based　on　computer　vision　technology　is　introduced.　The　template　matching　technology　is　used　to　locate　the　plum　needle,　and　the　teeth　values　of　stand　water-meter　and　the　under-verified　water-meters　are　counted　while　verifying.　When　the　stand　water-meter　count　to　the　set　value,　the　system　can　automatically　stop　the　counting　and　calculate　the　error　of　each　under-verified　water-meter　and　judge　that　the　under-verified　water-meter　is　qualified　or　not　by　the　error.　Field　experimental　results　show　that　the　system　has　a　higher　accuracy　and　works　well　on　wet-dial　water　meter　than　that　using　laser　reflection　measurement　method.　©　2017,　Acta　Metrologica　Sinica　Press.　All　right　reserved.