Monocrystalline　silicon　is　one　of　the　main　materials　that　is　used　to　make　silicon　solar　cells.　However,　all　kinds　of　defects　existing　in　monocrystalline　silicon　have　a　great　influence　on　the　photoelectric　conversion　efficiency.　In　order　to　solve　this　problem,　air-coupled　Lamb　waves　testing　method　is　proposed　to　achieve　rapid　quality　evaluation　of　monocrystalline　silicon　products.　The　dispersion　curves　of　Lamb　waves　in　anisotropic　monocrystalline　silicon　are　calculated　theoretically.　The　velocity　distribution　of　Lamb　waves　at　different　directions　is　obtained.　A0　mode　of　Lamb　waves　is　excited　in　the　monocrystalline　silicon　of　(001)　crystal　plane　by　the　air-coupled　transducers.　The　relationship　between　the　incident　angle　of　Lamb　waves　and　the　amplitude　of　signal　at　200　kHz　is　investigated,　by　which　13°　is　chosen　as　the　optimal　incident　angle.　The　phase　velocity　is　calculated　by　phase　spectrum　method.　Experiment　results　show　a　great　agreement　with　those　theoretical　values.　The　group　velocity　is　measured　by　amplitude　of　wave　packet　method　and　the　correlation　function　method.　The　deviation　by　the　latter　method　is　smaller　to　acquire　the　group　velocity.　Scanning　method　is　used　to　detect　the　defect　in　the　monocrystalline　silicon.　The　location　and　size　of　the　defect　is　reconstructed　by　calculating　the　correlation　coefficient　of　the　received　signals　and　reference　signals.　©,　2015,　Journal　of　Mechanical　Engineering.　All　right　reserved.