To address the difficulty of analyzing qualitatively and measuring quantitatively the correlation of underwater acoustic array element domain data before and after angular domain separation through experiments, a simulation method is proposed to perform correlation simulation analysis on the input and separated array element domain data in the azimuth and distance directions. Some typical seafloor echoes are used as inputs to the linear array from different directions as the simulation model. The correlation index between the input and the separated data is simulated. By pre-emphasizing on the ends, the simulation results show that the data of the typical seafloor echo input has better correlation with the data of the angular bandpass filter output in the azimuth directions. The results show that the correlation coefficient of reef bottom echoes has increased from 0.988 1 to 0.999 8, the correlation coefficient of sand and mud bottom echoes has increased from 0.934 2 to 0.996 7, and the correlation coefficient of mud bottom echoes has increased from 0.838 8 to 0.958 1.