To reduce the influence of noise on the high frequency ultrasonic detection of flip chip defects, a sparse denoising method of high-frequency ultrasound signals based on the multipath matching pursuit (MMP) is proposed. The MMP algorithm is used to obtain the atoms which are globally optimal. Aiming at the excessive calculation of MMP, the setting thresholds and the introducing pruning operations during iteration are introduced. To avoid the excessive calculation amount caused by the increase of the dictionary dimension, the contiguous atom dictionary is established to adjust the reconstructed signals and realize the noise suppression. Proved by simulation and experiment, the proposed method can effectively remove the noise in high-frequency ultrasonic detection signals of flip chip. Compared with MMP, the proposed method can improve the signal reconstruction accuracy and the clarity of B-scan by adding a small amount of computation.