Regarding the performance degradation caused by the traditional method of covert underwater acoustic communication, in this paper we propose a bionic underwater acoustic communication technology on the basis of differential Pattern time delay shift coding system and dolphin whistles. The signal band of dolphin whistles is narrow and the intervals between information signals are different, and the cross-correlation is very weak. Dolphin whistles are used for synchronization and Patterns, for the time interval between dolphin whistles conveys the information bits. The mimicked version of communication signal is not easy to detect and intercept, and the special encoding method of differential Pattern time delay shift also makes the information not easy to decipher, so this bionic underwater acoustic communication technology has strong covert and confidential nature and it also has an excellent performance in anti inter-symbol interference and anti Doppler effect. A tank experiment is conducted for this system. At SNR 0 dB and relative movement, the user message is recovered at an effective data rate of 67 bit/s with low bit error. It is proved that the system has an effectiveness, robustness and covert nature.