The sources of inherent error for 3D laser scanning system are analyzed.Combined with the mathematical model and experimental data,the correction algorithm is proposed,and it is verified in experiments.The characteristics of inherent error are analyzed from the theory of statistics.Considering the output speed and accuracy,the error of laser range finder can be reduced through increasing the average number.The dynamic angle error of motors is obtained by using the least-square method,and then the actual angle is gotten after rectification.For the nonlinear scanning distortion of dual galvanometric system,the pillow-shaped distortion can be reduced through changing the scanning range.In this paper,the inherent error correction algorithm is analyzed by Matlab,and is verified through some experiments.The experimental results show that the precision of 3D laser scanning system has a greater increase after the correction of ranging error,angle error and pillow-shaped distortion.