Abstract: For the direction estimation of the ship target by the binary hydrophone array,a time-delay difference estimation method of the ship radiation noise based on the stochastic resonance is proposed.A stochastic resonance filtering is designed and used to extract the local time when the ship propeller rotation noise appears in the signal received by the binary hydrophone array.Then the cross-correlation of the filtering results is used to estimate the time-delay difference between the ship radiation noise reaching the two hydrophones.By 200 times simulation with an input signal to noise ratio of 5 dB,the normalized mean square error of the time-delay difference estimation of the proposed method is an order of magnitude less than the method based on the cross-spectrum.The experiment results on the sea have shown that the time-delay difference between the ship radiation noise reaching the two hydrophones can be estimated accurately by the proposed method with a distance of 10 km.By the proposed method,the direction of the ship propeller rotation noise can be estimated accurately by the binary hydrophone array.