Abstract: Gas content, temperature and pressure are three important parameters. They reflect the characteristics of oil. Howerver they are easily ignored in the simulation analysis of axial piston pump. In order to explore the influence of oil characteristics on the flow pulsation at the outlet of axial piston pump , the simulation model of axial piston pump was established based on AMESim. The flow pulsation simulation of axial piston pump under different gas content, temperature and pressure was carried out . The results show that the oil characteristics have a great influence on the flow pulsation of axial piston pump. The flow pulsation characteristics of axial piston pump decrease with the increase of oil gas content, oil temperature, and system pressure.