Method for correcting liquid level reading of low-temperature barrel pump

The invention discloses a low-temperature barrel pump liquid level reading deviation rectifying method which comprises the steps that an upper liquid level meter opening of a pump barrel in a barrel pump is connected with the first input end of a differential pressure transmitter used for liquid level calculation through an upper pressure guiding pipe, and a lower liquid level meter opening of the pump barrel is connected with the second input end of the differential pressure transmitter through a lower pressure guiding pipe; the pump cylinder can store a target liquid medium; the lower pressure guide pipe is filled with a first gas medium under the operating pressure of the pump cylinder, and the condensation temperature of the first gas medium under the operating pressure in the pump cylinder is lower than the temperature of the target liquid medium; and the target liquid medium cannot enter the lower pressure guide pipe to form a liquid column in a mode of absorbing the first gas medium through compression