In order to describe the pressure at the valve core of a valve,the CFD technology and time series analysis method were used to model the pressure at the valve core.The flow field simulation of the fuel metering system was carried out,and monitor was set at the valve core to obtain the pressure value;the ARMA-ARCH model of the obtained pressure was established by using the time series method.The model was used to predict and compared with the original sequence.The results show that the model fits well.