The present disclosure provides a laser point cloud positioning method and system. The method comprises: converting laser point cloud reflection value data and height value data matched with a current location of an autonomous vehicle into laser point cloud projection data in a ground plane; assigning a weight for a reflection value matching probability and a height value matching probability of the laser point cloud projection data and a laser point cloud two-dimensional grid map, and determining a matching probability of the laser point cloud projection data and the laser point cloud two-dimensional grid map; determining a location of the autonomous vehicle in the laser point cloud two-dimensional grid map based on a matching probability of the laser point cloud projection data and the laser point cloud two-dimensional grid map. The present disclosure is employed to solve the problem in the prior art that when the laser point cloud matches with the map, an undesirable matching effect is achieved by individually considering the reflection value matching or height value matching, or superimposing the two simply. The present disclosure can improve the laser point cloud positioning precision, and enhance robustness of the positioning system.