The present invention relates to the embedding and extracting method of wavelet chaotic semi-fragile digital water print. Original image is 2D two-stage wavelet analyzed to obtain {LL2, HL2, LH2, HH2, HL1, LH1, HH1}, where, the pixel grey of LL2 sublayer is mapped to form chaotic initial value and chaotically iterated for several times to form water print image. Then, based on the quantized medium frequency coefficients { HL2, LH2, HH2}, and by means of the extreme sensitivity of chaos to the initial value and the excellent temporal frequency characteristic of wavelet, the distortion to water print image is precisely located. Via flexible regulation of quantized parameters, the robustness against baleful attack is obtained. The method of the present invention has stable performance, fastrealizing speed, strong robustness to baleful distortion and excellent distortion locating and proving capacity.