Aiming at the challenge to subsequent transmission and storage caused by large amount of data in array guided wave detection, a segmental hybrid compression algorithm is proposed in this paper. Based on the high amplitude and correlation characteristics of damage scattering signal, the detection data is divided into high and low fidelity segments. To consider both compression ratio and the fidelity of damaged signal, LOPCM lossless compression method is designed for the high-fidelity segment, and JPEG lossy compression algorithm is applied for the low fidelity segment. After constructing experimental platform, the measured signals are obtained and compressed. The effectiveness of LOPCM method was verified by comparison. The influence of the piecewise hybrid compression algorithm on the imaging accuracy is evaluated by investigating the overall error index of the signal and combining with the reconstructed data imaging results. The results show that the proposed algorithm can effectively reduce the amount of data while ensuring the accuracy of damage imaging, and it can better meet the requirements of data compression in array guided wave detection than only using lossless or lossy compression.