Due to low cost and high maneuverability and the reserve of original hydraulic system, the electric hydraulic coupling steering system is widely applied in tractor automated driving, but it is still unclear about the steering scheme characteristics which is existing in the process of the steering system. In the research process of the steering system, the technicians have some problems, such as the acquisition of experimental data subject to the current experimental conditions, the difficulty of the acquisition and recording of steering data, and the cost of manpower and material resources in the field debugging and installation of the tractor steering device. Based on this, a hardware in the loop of electric hydraulic coupling tractor steering test platform was designed. The design process of the platform parameters mainly considered the power loss, and in order to meet the performance requirements of the electro-hydraulic coupling steering system, the precision design and range design were carried out. Through the overall parameter design, the parameter calculation model of the electro-hydraulic booster and the resistance loading system was obtained, and the control and mechanical model simulation of the electro-hydraulic coupling steering system were established based on AMESim to optimize the parameters. The test platform can realize simulation of steering resistance moment under different soil conditions, automatic compensation control of active resetting torque of steering system and the response characteristic analysis and experimental verification of the electro-hydraulic coupling steering system of tractor and the automatic driving test, including path tracking. Through the hardware in-loop control scheme based on dSPACE and PXI, all kinds of steering condition tests were carried out. The results showed that the resistance loading simulation system can realize dynamic loading according to different driving conditions and other parameters, and the response speed and control accuracy can meet the requirements of field resistance simulation and electro-hydraulic power steering system can produce better smooth power with a good sense of steering. Furthormore, the control system can cooperate with each sensor hardware, so that the tractor electro-hydraulic coupling steering test platform had a good response characteristics, which can truly restore the tractor steering process, and provide a good reference for technical personnel.