Abstract: It is difficult to isolate the signal withmessages of structure's mini-faults in vibration detection methods. Thispaper proposes a method of wavelet analysis and modern spectrum estimationtechnology to extract the weakness elastic wave signal that representsstructure's cracks characteristics. For aspecimen with crack, the experimental results show that this method canimprove the accuracy of the crack identification from the vibrationsignal. It willbe used in the non-damage detection technology for mini-faults inengineering practice.