Abstract: In recent years, there has been a growing interest in various applied aspects of underwater acoustic (UWA) communication, such as telemetry, remote control as well as speech and image transmission. UWA channels can be characterized as rapidly varying time-frequency-space dispersive ones, which lead to low transmission rate, limited bandwidth efficiency, and high inter-symbol interference. At present, large amount of sonar systems with large array on ships are with multi-channel structure. In this paper, the multi-channel structure is taken advantage of realizing multi-channel diversity and equalization, so that the inter symbol interference (ISI) in UWA communication can be reduced.