Abstract:A negative flow control system of the bucket of multiway valve was built by using AMESim platform. The relationships between output flow and spool stroke under different load conditions were obtained by simulation,then the speed of oil imports of FLUENT simulation models at different spool stroke was determined. Based on FLUENT simulation, it is found that with spool stroke increasing, the steadystate flow force on the spool increases first and then decreases,with opposite direction to the spool movement, tending to close the valve port. And the greater the load, the smaller the steadystate flow force. Through error analysis, it is found if ignoring the steadystate flow force, a larger calculation error will be resulted in when calculating the operating force of the spool. Therefore, it is necessary to take the steadystate flow force into account when establishing the static force balance equation of spool.