In this work, a new defect identification method has been proposed in an attempt to detect the bonding quality of ceramic matrix composites. The method is based entirely on dynamic time warping (DTW) and simulation analysis. Aiming at two different characteristic defects of the glue layer (I) and glue layer (II) of CMC, the transfer matrix method is employed to model and simulate the defects in the bonding structure. On the basis of this, a dynamic time warping algorithm is used to regularize the simulation waveform and the actual waveform in time sequence, and the correlation coefficient is employed for the estimation of waveform similarity after regularization. In comparison with the traditional similarity evaluation standard of the DTW algorithm, the improved DTW algorithm has better waveform classification ability for the glue layer (I) and glue layer (II). The classification accuracy of debonding defects of the glue layer (I) is more than 95%, and that of the glue layer (II) exceeds 90%. Additionally, compared with the conventional terahertz imaging method, correlation imaging is appropriate for different characteristics of defect signals and has an improved defect-recognition effect.