Agricultural machinery driverless system is the basis for realizing precision agriculture. Research and development of agricultural machinery driverless system is an effective way to alleviate the shortage of labor force and realize precision agriculture. This paper introduces the latest progress in the navigation and positioning technology, navigation path planning technology and automatic steering technology of agricultural machinery in China and abroad. The navigation and positioning technologies of agricultural machinery based on GPS positioning technology, Beidou positioning technology and visual navigation are expounded respectively. The global path planning algorithm based on full coverage path planning and global point-to-point path planning is expounded. Local path planning based on obstacle avoidance and tracking, and automatic steering technology based on motor power and electronic hydraulic control. These technologies have been relatively mature after years of development, and have been widely applied in agricultural production practice. However, there are still many problems, including the positioning technology is vulnerable to environmental interference, the utilization rate of path planning technology data is low and the dependence on environmental information is high, and the automatic steering technology is complex in the modification process, and it is easy to damage and difficult to maintain in harsh field operations. Based on the above, it is proposed that integrated navigation, multi-sensor fusion technology and modular automatic steering device are the future research directions of agricultural machinery unmanned driving system.