To enable laser proximity fuze of anti-radiation missile(ARM) to detect and recognize radar targets, a detection and recognition method put forward based on multi-beam narrow laser light additionally, a mathematical model established change in distance measured by laser fuze to recognize targets' height and width. By calculating Lebesgue integral of target occurring probability distribution function, the optimal light beam angle achieved, which maximize the detection probability with a fixed light beam number. Besides, typical munitions-target encounter simulation carried out. The result shows that the detection probability increases with decreas of ARM trajectory angle and of the height of target antenna, and the optimal light beam angles are dense in the middle of detection plane and spare in the edge.