Abstract: GNSS multipath signals widely exist in complex navigation and positioning scenarios such as urban canyons. Although the multipath signal interferes GNSS receiver and reduces positioning accuracy, it provides environment information around the receiver. Based on the coupled amplitude delay locked loops algorithm (CADLL) which senses GNSS multipath signals and extracts feature parameters, a particle filter-based reflection plane parameters estimation algorithm is designed and implemented. The algorithm can enhance the receiver's environment perception in the GNSS multipath environment, the corresponding information can be applied to the fields of scene perception, collision avoidance, path planning and positioning augmentation. GNSS multipath signal recording and algorithm testing are carried out in a static environment. The experimental results show that the algorithm can effectively estimate the position parameters of the reflecting plane. The root mean square error (RMSE) of the azimuth angle of the reflection plane is less than 10 degrees, the RMSE of the elevation angle is less than 5 degrees, and the RMSE of the distance is less than 10 meters.