The invention discloses a multibeam echosounder self-adaptive dynamic regulating system and regulating method. The self-adaptive dynamic regulating system comprises display control software, a transducer, a gain control unit, an AD sampling module and a processor, can automatically regulate the gain of received signals, also can automatically regulate the transmitting power, and can regulate circularly and dynamically by coordinating the gain of the received signal and the transmitting power, so that the voltage of the received signals keeps at the stable interval, and the efficient operation is ensured; the technical problem that in the prior art, the gain of the received signal and the transmitting efficiency are regulated manually, so that the efficiency is low, and the measurement precision of the multibeam sounding system cannot be guaranteed; the multibeam echosounder self-adaptive dynamic regulating system and regulating method conform to the development trend of the modern automatic measurement.