Liquefaction storage tank monitoring device and liquefaction storage tank

The utility model provides a liquefied gas storage tank monitoring device which is installed on a tank body, a liquid level meter is arranged in the tank body, and the liquid level meter comprises an anti-explosion shell, a liquid level input line, a liquid level output line and a controller. The explosion-proof shell is detachably mounted on the tank body, and an accommodating cavity is formed in the explosion-proof shell; one part of the liquid level input line can be connected to the tank body and is electrically connected with the liquid level meter, and the other part of the liquid level input line is accommodated in the accommodating cavity; one part of the liquid level output line can be electrically connected with an external display device, and the other part of the liquid level output line is accommodated in the accommodating cavity; the controller is accommodated in the explosion-proof shell; the controller can be in communication connection with an external tank car and is used for receiving the m