Aiming at the problem of equipment parameter fluctuations in liquefied natural gas（LNG） terminal when operating conditions change, the dynamic model of LNG terminal process flow was established by using HYSYS software. The empirical trialand-error method was used to analyze the influence law of proportional, integral and differential coefficients of PID controller on tank pressure, re-condenser level and low-pressure pump flow to reduce the fluctuation and un-stability in the operation of LNG terminal.The results show that in the tank pressure control system with proportional and integral control, when the proportional coefficient is changed from 1 to 4, the recovery time to the set value can be saved by 55.6% and the recovery time can be significantly shortened by adding integral control. In the re-condenser level control system, single proportional control can be used under the condition that static difference is allowed when the proportional coefficient is changed from 0.5 to 5.0, the recovery time to the set value can be saved by 62.9%, and the integral coefficient has no obvious effect on the level control. In the low pressure pump flow control system with proportional and integral control, the change of the integral coefficient has a more obvious effect on the flow control system when the integral coefficient is reduced from 3.0 to 0.5, the recovery time to the set value can be saved by 72.9%. Finally, the recommended parameters of the three control systems were given, which can provide reference for the selection of PID controller parameters in LNG terminal.