Abstract: Based on echo light data,this article explicates the target echo light azimuth-distance denotation method,the multi-beam light scalar and vector denotation method,the target echo course and multi-beam echo light combined analysis method and the target length estimation by use of echo light distribution characteristic.These methods are significant to the analysis of target characteristics including fixed lights,moving lights,double lights,target azimuth trend and length estimation,and have important application value in torpedo homing and target identification.