Abstract: To explore the possibility and performance of the bionic signals and detection method for small target sunk at sea bottom, this paper studies and analyzes the characteristics of three different dolphin-clicks sonar signals in time domain and frequency domain, ambiguity function and anti-reverberation respectively; and uses compute simulation to conduct the detections of the small target at sea bottom under complex background. Both the theoretical analysis and simulation results show that: the dolphin-clicks sonar signal with more frequency overlaps has the best performance in anti-reverberation among the three signals; the performance of the bionic detection method is better than the standard sonar detection method. Dolphin-clicks sonar signal and bionic detection can be a kind of novel signal and detection method to detect small target sunk at sea bottom.