Acoustic sources' localization by beamforming technology in an enclosed space is not easy due to the interference of reflected waves. Previous methods of beamforming are based on a free field hypothesis; therefore, problems are appeared when this technology is used in reverberation. The paper presents a method combined with particle velocity beamforming for locating acoustic sources in an enclosure by using double parallel surfaces beamforming array. The interference of reflected waves can be removed by taking twice-weighted for double layer array. The performances of this method are simulated by locating multiple coherent acoustic sources in shallow water. The simulation results show the effectiveness of proposed method in an enclosed space