Obstacle detection and obstacle avoidance technology is the key technology for automatic navigation of agricultural robots. Accurate perception and avoidance of obstacles can ensure the safe operation of agricultural robots in complex environments, reduce labor costs and improve production efficiency. This article outlines the application of different types of single sensor technology and multi-sensor fusion technology in obstacle detection of agricultural robots from different angles. First of all, the research progress of using a single sensor such as RGB camera, panoramic camera, binocular camera, and depth camera for obstacle detection is reviewed, and the advantages and limitations of each sensor are expounded in detail. Secondly, it outlines the research progress of multi-sensor fusion technologies, such as the fusion of vision sensors and lidar, the fusion of vision sensors and millimeter-wave radar in obstacle detection, and analyzes in detail the characteristics and advantages of different sensor fusion technologies. Advantages. Agricultural robots are mainly divided into large agricultural machinery and small agricultural robots. For different types of agricultural robots, the research progress of agricultural robot obstacle avoidance technology in recent years is systematically reviewed, and the application characteristics, key challenges and development trends of various technologies in complex agricultural scenarios are analyzed. Finally, the research status quo and challenges of obstacle detection and obstacle avoidance technology of agricultural robots are summarized and prospected, with a view to providing relevant theoretical basis and technical reference for the rapid development of automatic navigation of agricultural robots.