Abstract: To avoid the risk that the receiving station may be exposed due to scattering the active signal, the bistatic low probability of interception (LPI) technique based on acoustic shielding technique is proposed. Utilizing the acoustic multi-path feature of the direct signal, the original signals are pre-processed by acoustic shielding at the transmitting station to get the LPI transmitting signals of bistatic sonar. Simulation results show that:compared with original signal, when transmitting the LPI signal, the interception signal received by the target attenuates significantly; the middle part of the interception signal attenuates more than the both sides of the interception signal do in time domain; however, the target scattering signal received by the receiving station essentially unchanged. The proposed LPI technique enhances the anti-intercept ability of the scattering signal from the receiving station and reduces the quality factor of the target without affecting that of the receiving station. And, the proposed LPI technique helps the receiving station to maintain stealth and improves the underwater-acoustical countermeasure ability of the bistatic sonar. The traditional LPI waveform designs only change the signal power distribution along the time-frequency axis and the chaos characteristic to increase the complexity of detecting signal. The proposed method really reduces the energy of the interception signal. The proposed method can apply to all kinds of broadband signal and provides a new idea for LPI sonar.