A　high-precision　ultrasonic　microscopy　measurement　system　was　developed　in　order　to　non-destructively　test　the　mechanical　properties　of　metal　sheet　and　coating　materials.　The　whole　system　is　based　on　acoustic　microscopy　techniques.　The　ultrasonic　waves　are　excited　and　received　by　a　line-focus　transducer.　This　paper　presents　the　principles　and　methods　of　the　surface　wave　velocity　measurements　using　this　system.　The　surface　wave　velocity　is　measured　along　different　propagation　directions　on　a　(100)　silicon　wafer.　The　results　of　the　measurement　have　good　repeatability　and　consistency　in　the　symmetry　directions.　They　indicate　that　the　system　shows　high　accuracy　and　fine　stability　at　defocusing　positions　and　rotation　angles.　The　system　meets　the　measurement　requirements　for　isotropic　and　an　isotropic　materials.　In　addition,　this　acoustic　characterisation　method　can　be　used　to　measure　the　wave　velocity　at　different　frequencies,　so　the　dispersion　curves　of　the　sheet　metal　and　coating　specimen　can　be　measured　by　this　method.　As　a　result,　the　mechanical　properties　of　the　materials　can　be　calculated　by　fitting　the　theoretical　and　experimental　dispersion　curves.