Abstract: The automatic driving system of agricultural machinery is one of the key technologies of unmanned farms. It had been applied to agricultural equipment such as tractors, combine harvesters, and agricultural robots, and had become a hot spot in academic research. From the aspects of hardware foundation and underlying technology, the principle of agricultural machinery automatic driving technology was sorted out in detail. Its core content lies in the three links: environmental perception, decision-making and planning, and control and execution. The implementation principles of each link and the main research achievements at home and abroad were analyzed one by one. The advantages of agricultural machinery automatic driving compared with manned driving are operation accuracy, efficiency, and reduced operation intensity, and the shortcomings are dynamic path planning, automatic headland steering, system reliability, and safety. The global automatic agricultural machinery driving industry environment was analyzed.The competitive environment of the Chinese market is highlighted. The price and service system of automatic agricultural machinery driving system, the level of mechanization, and the low education level of downstream consumers were the main factors restricting the development of the industry. The future research hotspots will focus on the cooperative operation of the cluster, obstacle detection, initiative obstacle avoidance, and integration with 5 G to shaping unmanned agriculture was predicted. It had great reference significance for the construction and development of unmanned agriculture and the reconstruction of China’s agricultural production model.