Abstract: Three-dimensional solid reconstruction is the technological basis of engineering planning, design and management. By using AutoLISP programming method and employing the interpolation theories with inverse distance weighted method and Delaunay triangulation method, a program is developed for engineering data processing. This program can carry out a discrete point data interpolation, three-dimensional digital terrain model generation, three-dimensional solid reconstruction and engineering earthwork calculation. With the proposed method, the program has strong interoperability, easy and visual operability, wide applicability, and high accuracy. At the same time, the program can greatly reduce the working strength of engineers and improve the work efficiency. And furthermore, the application of this program is not only beneficial to the designers to estimate and utilize the results in engineering calculations, and is helpful for designers to make a timely design adjustment, so as to optimize the engineering design and reduce the proiect costs.