Abstract: In this paper, the hyperspace cancellation by coordinate zeroing (HCC0) algorithm is improved to make it suitable for underwater acoustic mobile multi-user communication systems. The improved HCC0 algorithm combines multi-channel processing and introduces spatial gain to further overcome the multiple access interference (MAI) in multi-user communication systems. Simulation results demonstrate that the proposed algorithm can effectively overcome the interferences from the interfering user in the two user scenario at the signal to interference ratio (SIR) of -10 dB. When the bit error rate reaches 10^-4, the performance loss is around 1 dB compared with a single user without interference. Compared with the traditional successive interference cancellation (SIC) algorithm, the improved HCC0 algorithm performs better in underwater acoustic moving scenes. The lake test data show that MAI is effectively suppressed by using the improved HCC0 algorithm when the desired user is interfered by two other users at different speeds, and the output signal to noise ratio (SNR) of the desired user is about 8 dB higher than the original data, which proves the effectiveness of the algorithm.