The utility model discloses a portable digital walkie -Talkie communication system under water, including signal acquisition broadcast module, become the speech input signal quantization digital voice signal or restore and play and play with the reduction the location information acquisition between target node, coding and decoding module is to the compression and the decompression of digital voice signal or framing signal, control module is right through coding and decoding module compression or the control of the signal after decompressing etc, modem control module is to the modulation or the demodulation of the signal after compression or the decompression, transducer end received signal's input is accomplished to the analog front end module, enlargies and gathers, data storage module accomplishes the storage to original data, the utility model discloses possess from adaptability underwater sound channel, can carry out parameter configuration, mode switch, range selection, compression code check in addition in a flexible way and switch over, reduction pronunciation effect after decoding is clear, and the tone quality nature more possesses miniaturized, modularization, the system integration of being convenient for, advantages such as easy transplanting.