Abstract: Underwater acoustic detection was an important technique used in illegal survey and detection by foreignsurvey ships and by ships of underwater cultural relics.The ocean underwater acoustic detection signals were classi-fied according to the acoustic characteristics of signals.It was divided into broadband middle and low frequency sig-nals and narowband high frequency signals.Four representative ocean underwater acoustic detection signals of sub-bottom profiler signal,spark sound source signal,side scan sonar signal and single frequency bathymeric signalhad been measured in Xinghua Bay,Fujian Province,according the acoustic characteristics and theircorespondingclassification had been given.Among them,the sub-bottom profile signal was the middle and low frequency signaland its signal type was detemmined.The spark sound source signal was also the middle and low frequency signal butits signal type was broadhand pulse.The side scan sonar signal and single frequency bathymetric signal were nar-rowband high frequency signal.Through the analysis of 4 groups of measured acoustic detection data,the analysisand extracted methods of corespondingtypes of ocean underwater acoustic detection signals had been given.Amongthem,the middle and lowfrequency signal which its signal type was determined and narrowband high frequency sig-nal can be extracted by band-pas filtering based on time-frequency analysis,the broadband pulse middle and lowfrequency signal can be tested and extracted by wavelet scale corelation filtering method based on time frequencyanalysis.Combined with the acoustic characteristics of the known underwater acoustic detection signals,the meas-ured ocean underwater acousticdetection signals can be identified.