Abstract: The control effect of gas and water damage is an important factor affecting the safety of coal mining. The measurement accuracy of borehole trajectory directly affects the control effect of gas and water damage of coal seam in mining area. In order to improve the calibration accuracy of the inclinometer and its adaptability to random errors, aiming at the problems that the current multi-position calibration method of the inclinometer does not consider the effect of symmetry on error reduction, the measurement error is introduced in angle rotation correction, and the calibration time is reduced, a multi-point calibration and error simulation method is first established. The effects of calibration points, filtering methods and angle rotation correction on inclination calibration are simulated. It is proved that when the calibration points are greater than 100, the calibration points have less influence on calibration results. The median filter has better filtering effect than the mean filter, and the filtering effect is better when the filter points are greater than 6, and the traversal optimization angle rotation correction can reduce calibration errors. All reference points in the calibration method are symmetrical about the coordinate plane, and any point in the calibration method can find another point corresponding to it. The influence of the interval of reference points on the calibration results is simulated, and the 108 point calibration method with a calibration interval of 20° is preferred. The calibration error of the full-symmetric clinometer calibration method is about 38% of that of the full-space 276 point method and 39% of that of the full-space 120 point method. The actual calibration error of the instrument is less than 1°. Compared with the full-space multi-position calibration method which does not consider symmetry, the full symmetry method can reduce the influence of measurement error on calibration coefficient and has higher calibration accuracy.