A novel technique, based on wavelet-transform analysis, was introduced for the carrier-envelope phase extraction in this paper. With wavelet analysis technique, the carrier-envelope phases of amplified ultrashort optical pulses were directly extracted from the spectral interferences. The technique need no Fourier-transform and filter procedure, therefore, the uncertainty introduced from the filter is avoided naturally. Wavelet-transform technique extracted accurate carrier-envelope phase, therefore we hope it can find applications in the measurements and characterizations of few- to mono-cycle femtosecond optical pulses.