Based on the mechanical structure and oil line flow of the open non-reactive hydraulic steering gear, the AMESim model of steering gear was built by using HCD library of AMESim. According to the special purpose vehicle overall design requirements, the parameters were set reasonably, the steering gear was simulated, the influences of different signals of steering on the steering gear performance were analyzed. The results show that the model has characteristic of fast dynamic response, smooth steering displacement output,so it meets the design requirements.