The ability to perceive the vehicle’s local environment is one of the main challenges in the field of Unmanned Ground Vehicles(UGV). Many kinds of positive-negative sensors are used to obtain the information of the vehicle’s local environment. The environment perception system is in charge of processing, fusing and understanding the information. The system also realizes the detection of road and obstacles and the classification of terrains. Autonomous navigation and path planning of UGV are based on the process results of perception system. In this paper, the architecture of environment perception system is introduced. The methods of road detection and obstacles detection are discussed, and then the detection results of these methods are analyzed. The existing problems and the future development trends of the environmental perception system are summarized and prospected at last.