Abstract: In order to implement the effective anti-reconnaissance to unmanned aerial vehicles (UAV), the feasibility of effective monitor for UAV by a laser detecting system was analyzed, the model of laser transmittingreceiving system and optoelectronic imaging system of UAV was established, and the characteristics of specular scattering light of the UAV imaging lens and reflecting light of focal plane were simulated. Taking a UAV at the altitude of 10,000m as an example, the application feasibility of the detecting system with two kinds of reflecting light was analyzed, and the available incident angle range of laser detection was obtained. The characteristics of light distribution on the photosensitive face of the detecting system and reflecting light change when the detecting laser was dynamically scanning were analyzed. The results show that the intensity of the focal plane reflecting light from imaging lens is much higher than that of the specular scattering light, and it has a very good characteristic of returning to the original path. And also it can detect and locate the target (UAV) by the aid of the reflecting light from the focal plane at the FOV coverage range of the imaging system on UAV.