Strain　mode　was　adopted　to　investigate　the　detection　of　structural　crack　location　and　damage　extent　by　applying　continuous　wavelet　analysis.　The　relationships　between　module　maximum　and　crack　location,　Lipschitz　exponent　and　damage　extent　were　built,　which　solve　the　problem　of　incomplete　reflection　of　damage　extent　by　strain　mode.　Numerical　simulations　show　the　method　of　damage　detection　based　on　continuous　wavelet　analysis　can　identify　rather　well　the　damage　location　and　its　extent.　With　the　increase　of　damage　extent,　the　Lipschitz　exponent　decreases　for　single　crack　as　well　as　multi-cracks.