Abstract: In response to the current problems of low intelligence and insufficient application of agricultural machinery, an automatic navigation system for agricultural machinery is designed based on a Linux system that operates through a graphical interface. The system uses the GNSS dual positioning and orientation module to solve the problems of inaccurate heading and unstable positioning in the past agricultural machinery automatic navigation process. Based on the main loop farming mode in Shanxi Province, design algorithms for straight lines and automatic turning paths in path planning. The turning path route is optimized using a fourth-order Bessel curve, which reduces the operating load of agricultural machinery and mounted machinery. The system integrates a steering drive module for angle acquisition, making installation more convenient and performance more stable. Using the Jingtuo Benye 604 tractor as the experimental platform, the tractor’s straight path operation tracking and turning path tracking were carried out. After multiple experimental results analysis, the obtained experimental data can meet the requirements of actual field operations.