Abstract: The tractor steering system is hydraulically controlled and implements full hydraulic steering. The hydraulic steering system designed in this article achieves the steering function of tractors in both manned and unmanned driving modes. Through prototype testing, it has been verified that the tractor can turn normally in two modes, providing a reliable solution for the steering design of unmanned tractors in the industry. Finally, the article presents common faults in the use of hydraulic steering systems and provides a detailed analysis of the troubleshooting process, in order to provide ideas and methods for fault diagnosis of hydraulic steering systems.