Double-weighing volume and density measurement method

The invention provides a double-weighing volume and density measurement method, which comprises the following steps: based on the nature of a hydrostatics buoyancy measurement principle, carrying out double weighing on a measured object in a preset atmospheric pressure measurement interval, and constructing a double-weighing volume and density measurement model in the air so as to obtain the actually measured volume and the actually measured density of the measured object; constructing a thermal expansion error correction model according to the volume expansion coefficient of the measured object; correcting the actually measured volume and the actually measured density by using a thermal expansion error correction model to obtain a target volume and a target density of the measured object at a target temperature of 20 DEG C; and analyzing the uncertainty, and optimizing the double-weighing measurement model to output the target volume and the target density of the measured object after optimization. The doubl