This study presents a novel imaging method in passive sensing structural health monitoring (SHM), for locating impact damage in real-time on a plate-like structure. So far, many imaging methods have already been applied in active sensing SHM to locate the damages. However, seldom of the imaging methods can be directly used to locate the impact in passive sensing SHM. In order to avoid solving the hyperstatic hyperbolic equations and generate an informative image for locating the impact damage, the proposed method combines the imaging method with probability calculation. Moreover, to demonstrate the feasibility of the proposed method, the experimental results are presented and analyzed. From the results, the proposed method shows an interesting phenomenon that the accuracy of the impact localization depends on the impact position. Finally, a detailed analysis of the method accuracy is discussed.