Universal meter and re-calibration method thereof

The invention discloses a universal meter and a re-calibration method thereof, and relates to the technical field of measurement. The method comprises the following steps: acquiring an instruction for setting a to-be-calibrated measuring range under a to-be-calibrated measuring function of the universal meter; selecting at least two calibration points under the range to be calibrated; obtaining a stable signal at each calibration point so as to generate a calibration measurement value corresponding to each calibration point at each calibration point; for each calibration point, acquiring a real-time measurement value of the calibration point, and grouping the real-time measurement values corresponding to the calibration point to generate corresponding measurement groups; calculating fluctuation difference values of the measurement groups, taking the measurement group with the minimum fluctuation difference value as a reference group, and calculating an average value of the real-time measurement values in the