In recent years many optical reconnaissance systems have characteristic called “cat-eye effect”, it means that the incident light in such system can be reflected back along the same path of incidence. And these optical systems can also be called “cat-eye target”. The scanning-style target’s reflective surface appears in the focal plane at a certain period—Only when the reflective surface is in the focal plane that the target can reflect the incident light. Therefore, when active laser detection systems launch laser impulse to detect these targets, the detection result is uncertain. Current research has little analysis for uncertain detection result of scanning-style target. In order to describe such uncertain detection result, in this paper, we first analyzed the time factors and put forward detection probability formulas; Second, we use MATLAB to simulate the detection result of scanning-style cat-eye target, and we received the quantitative relationship curve between the frequency and the value of detection probability; Furthermore, we found that the value of detection probability is related to the detection time and the frequency of laser impulse. The result of the simulated experiment indicated that we could modulate the frequency of laser impulse launched by active laser system to increase the value of detection probability, it will help improve the detection quality of the active laser detection systems.