Abstract: Obstacle detection is a crucial technology in environment perception, which directly affects the safety and reliability of intelligent agricultural machinery equipment operation. People working in the fields, as non-structural and non-fixed obstacles, are important factors affecting the safety of agricultural machinery. This paper reviews the application of pedestrian detection sensor technology and pedestrian detection algorithms in China and internationally, focusing on the applicability of various detection technologies and algorithms in complex farmland environments. Firstly, the advantages, disadvantages, and applications ranging from single-sensor detection technology to multi-sensor fusion technology are summarized. Secondly, the research and applications of pedestrian detection algorithms using traditional methods and deep learning methods to deal with occlusion are analyzed. Finally, it identifies limitations of current technologies, such as relatively limited application of single sensor technology, insufficient stability of multi-sensor fusion technology, and limited effect of pedestrian detection algorithm in handling occlusion. This paper proposes prospects for the diversification of collected information, UAV-assisted obstacle avoidance, and the establishment of a complete farmland environment sensing system.