Cryogenic liquid storage tanks are generally equipped with a self-pressurization system. In order to ensure the normal supply of gas, the self-pressurization of the LNG storage tank is completed by a loop composed of a storage tank, a booster, and a booster regulating valve. During operation, the self-pressurized gas valve and liquid phase valve of the storage tank are set to open state, and LNG enters the self-pressurized vaporizer. In the vaporizer, the atmospheric environment is used as the heat source, and the heat exchange with the air is NG, and the NG passes through the gas phase pipeline. It flows through the BOG root valve of the storage tank and enters the upper gas phase space in the tank, which increases the pressure of the gas phase, thereby increasing the pressure of the LNG storage tank. With the continuous flow of LNG, the liquid level in the tank continues to drop, and the gas phase space continues to increase. In this way, the self-pressurized vaporizer is used to continuously plan LNG to increase the pressure in the tank, so that the pressure of the LNG storage tank continues to rise to achieve Required pressure.