Abstract: To solve the problem of target location by passive sonar, a target parameter estimation method based on generalized Radon transform is proposed in this paper. Firstly, the mathematical model for the time delays between the direct and surface-reflected path in the deep ocean direct area and the target motion parameters is derived. Secondly, the multipath-time-delay-time records (MTDTR) are obtained by solving the autocorrelation functions. Finally, the heading angle, the velocity, the initial azimuth of the target, and the initial range of the target to the hydrophone are obtained by simultaneously applying the generalized Radon transform to MTDTR of two hydrophones. The parameter estimation performance of the proposed method is verified by computer simulations and sea trials. The results of the southeastern Sanya sea trials suggest that the proposed method can be used to locate the surface target by using two acoustic pressure hydrophones deployed near the seabed. More specifically, under the conditions of the sea trial test, the range measurement error is less than 0.29 km over a distance of 12.71 km, which equates to a relative error of less than 3%.