Abstract: In order to accurately control the high level (HL) valve shutoff process for buried oil tank, the kinematics equation is established and then solved to get the valve shutoff speed, time and acceleration equations. The kinematics equation of valve core shutoff shows that, when the main structure of the control valve is determined, the valve shutoff speed, time and acceleration will be influenced by the orifice size - the larger the orifice is, the shorter the valve shutoff time is. The HL valve shutoff process is numerically simulated using the FLUENT software. The results show that the valve shutoff process presents an accelerated motion in which acceleration decreases gradually, and a water hammer phenomenon occurs. Therefore, it is necessary to adopt the guide rod to control the movement direction of the valve core.