Abstract: Underwater target localization and parameters(azimuth and range) estimation by the method of utilizing explosions as underwater sound sources are described. The narrow beam reverberation model of the target echo signal is researched to estimate the target azimuth in reverberation background. Estimation errors of target azimuth and range are studied and proved to approximately meet Gaussian distribution. Then the variance of target range error is deduced. Simulation experiments are applied to research the target range error and its standard deviation, and a series of measures to improve the estimation accuracy of target range are proposed. It is confirmed by the data processing results of simulations and lake experiments that the proposed method can accurately locate underwater target at a long distance on the condition of a certain underwater explosion range error.