Abstract: One of the countermeasures of modern intelligent torpedo is to emit signals with deceiving codes,so it is necessary to develop intelligent equipment against this kind of torpedoes.Receiving while emitting acoustic decoy can not be deceived by the pseudo codes,because it doesn't turn off its receiver while emitting signals,moreover it is able to measure the frequency of the torpedo searching signal in heavy interferences so as to control the emitting frequency varying with the torpedo searching signals,which enhances the anticapacity of decoy.The difficulty of suspended receiving while emitting decoy is suppressing the interferences of emitting sound,reflected sound and reverberation from sea surface and bottom.The zero-point directivity of vector sensor can be used to suppress the above-mentioned heavy interferences,and make the decoy realize detecting faint searching signal and measuring its frequency while emitting.