With the development of manufacturing, obtaining 3D data of objects surface effectively and precisely has been important. In this paper, laser radar is selected to gain 3D geometric data by comparing the current digital measurement techniques, and the measurement principle of laser radar is discussed in detail. For obtaining the whole surface points cloud of work piece and reducing the error of station moving, the mathematical model of station moving is established. This paper also analyzes the characteristics of points cloud data collected using laser radar, estimates the normals of scattered points with PCA method. Finally, the 3D surface of work piece is reconstructed using radial basis function interpolation.This system has the advantages of fast measurement speed, large measurement range and high degree automation.Because laser radar uses optical non-contact measurement mode, so there are no special requirements of the object surface.