Abstract: By means of analyzing the point source transmittance of the laser receiver with optical structure of cylindric cavity, the feasibility and relative light power demand to jam laser rangefinder with the stray light is investigated. According to the increasing incident angle of jamming light, three major mechanisms of stray light jamming, i.e., diffuse reflection-specular reflection jamming, double diffuse reflection jamming and single diffuse reflection jamming are presented. The corresponding PST function is also derived. Furthermore, the digital simulation using Tracepro software is adopted to verify the functions. The results show that under typical condition to jam the laser range finder reliably within 30°, the jamming light power should be 5×106 times than that of jamming at 0°, and