Using low-orbit satellites to achieve navigation augmentation is an inevitable trend in the integration of communication and navigation. The Ka-band has significant advantages in this scenario, but the integrated communication-navigation augmentation signals based on this band feature large bandwidth and high dynamics, which pose challenges to the efficient acquisition of signals. Through targeted analysis of the characteristics of Ka-band signals, an improved two-stage Partial Matched Filter-Fast Fourier Transform (PMF-FFT) acquisition algorithm is proposed.Simulation results show that under a given signal-to-noise ratio (SNR), the acquisition performance of the improved PMF-FFT algorithm for Ka-band signals is always superior to that of the traditional algorithm: the amplitude of the correlation peak is increased by 17.1% compared with the traditional algorithm, and the Doppler measurement error is reduced to 1.25 kHz. This can lay a foundation for subsequent precise tracking and pseudorange measurement processing.Meanwhile, the algorithm effectively balances acquisition gain and computational efficiency, and can be used for efficient acquisition and reception processing of signals in low-orbit Ka-band navigation augmentation systems.