Error compensation method and measurement error evaluation method based on biaxial symmetry etalon

The invention discloses an error compensation method based on a biaxial symmetry etalon. The error compensation method comprises the following steps: dividing a measurement space into a plurality of measurement areas; wherein the error levels in the same measurement area are the same, and the measurement error is increased with the same linear change coefficient along with the expansion of the measurement range; setting the linear change coefficient of the tau measurement area corresponding to the tau error level as ktau, and setting the correlation coefficient of the tau measurement area as delta tau = 1/ktau; matching a corresponding correlation coefficient for the node according to the measurement area where the node on the etalon is located and a correlation coefficient matching criterion; wherein the correction correlation coefficient of the node is equal to the product of the node weight level and the matching correlation coefficient; and compensating the error measurement valuecorresponding to each nod