The utility model discloses a hydrate detection system at bottom of coastal waters, detection system includes that the on -board subtotal drags the part deeply, the on -board part includes: synthesizemonitoring host, monitoring host sends to trigger and gathers pulse signal to the transmission is to dragging the part deeply, and the information at the bottom of the coastal waters of dragging somecollections deeply of receiving to confirm according to information at the bottom of the coastal waters the condition at the bottom of the coastal waters, drag the part including the data acquisitionunit deeply, gather pulse signal according to triggering, information at the bottom of the coastal waters of collection current position department, sparker gathers pulse signal production electric spark vibration signal according to triggering, multi -channel data acquisition electronic cabin is connected with comprehensive monitoring host, data acquisition unit and sparker respectively, will trigger collection pulse signal and transmit to sparker and data acquisition unit, and with information transmission at the bottom of the coastal waters of data acquisition unit collection to synthesizing monitoring host to the fresnel radius can be reduced, the resolution ratio of surveying is improved.