Abstract: Horizontal arrays is the common array form in underwater acoustic communication (UAC), however vertical arrays also has important application occasions. In this paper, a multichannel maximum-likelihood joint equalization and channel decoding algorithm for vertical array is proposed. Compared with the multichannel decision feedback equalization algorithm (M-DFE), which only superimposes the signals of each channel in the channel equalization, the proposed algorithm adopts the maximum-likelihood rule as the decoding criterion and integrates the information of each channel to calculate the decoding metric. In this way, the spatial gain is directly used for correction of decoding error and resistance of multipath fading, and the performance of UAC can be improved effectively. The simulation results show that when the error rate reaches 10^-3, the SNR required by the proposed algorithm can be reduced by 2 dB than the M-DFE algorithm. The experimental results show that, under different channel conditions, the communication rate of the proposed algorithm is more than 1.25 times higher than that of the M-DFE.