Abstract: This research focuses on the calibration and compensation methods for single-axis linear errors in inclinometer probes. The study begins with an analysis of the probe's technical parameters, working principles, characteristics, and installation methods during use and calibration, aiming to investigate the sources of measurement errors when applied in the construction and engineering monitoring fields. From these error sources, specific solutions are identified, employing the least squares method for compensation of the probe's single-axis linear error. A new calibration method for the inclinometer probe, based on an optical dividing head, is proposed. The study conducts experimental comparisons of measurement results before and after the compensation of single-axis linear error. The results indicate that the proposed method can significantly reduce the single-axis linear measurement error of the inclinometer probe. Measurement uncertainty is evaluated and analyzed to validate that the calibration method meets the requisite standards. Lastly, the effectiveness of the compensation method is verified through repeated installation trials.