Abstract: In order to study the factors of the energy consumption in the EHPS (electro-hydraulic power steering) system, hardware-in-loop simulation test bench was built. The test bench included a master platform, a steering wheel driving module, a test system module and steering resistance’s hydraulic loading modules. Energy consumption of main components of a certain type of EHPS system was tested by the bench, and the key factors of the energy consumption were studied by simulating the country road situation. The results showed that the energy consumption in EHPS system were significantly impacted by standby power, hydraulic oil temperature, viscosity, pressure drop of steering valve, as well as power of the steering rack. The research is benefit to development of new energy-saving EHPS system.