激光跟踪仪测距精度取决于激光干涉仪(IFM)和激光绝对测距仪(ADM)的精度，就目前技术水平而言，IFM测距精度远高于ADM 测距精度，因此需要对ADM 测距误差进行修正。本文采用三次样条函数对激光跟踪仪全程ADM 测距误差进行修正，并与线性误差修正方法进行了对比，结果显示三次样条函数能够更好地拟合误差曲线，改善修正后残余误差的均方差，均方差为0.007 mm，优于最小二乘直线拟合，从而提高激光跟踪仪测距精度和空间测量精度。

Laser tracker distance measurement accuracy depends on the accuracy of laser Interferometer Measurement(IFM) and Laser Absolute Distance measurement (ADM). Based on the current technology, IFM measurement accuracy is much higher than ADM measurement accuracy. So the ADM measurement error needs to be compensated in order to improve laser tracker measurement accuracy. The compensation method of cubic spline function and linear function is compared and analyzed. The results show that the residual error of cubic spline function compasation method is 0.007 mm, which is much better than that of linear function method (0.029 mm). The verification points also show the same result. The conclusion is drawn that cubic spline function can be used to better correct ADM error of laser tracker.