Abstract: Archaeological line graph can not only show the shape characteristics of cultural relics, but also serve as their essential archives. It is obtained by manual work traditionally with high time-consuming and low accuracy as well as may cause new damage to cultural relics. In this paper, a new method was proposed based on a 3D model of cultural relics to generate archaeological line graph automatically, and was applied to debris models of Terracotta Warriors. First of all, the debris models were obtained by laser scanning and were pre-treated such as denoising, hole filling and simplification. Then, the feature points were extracted from the model according to the normal dispersion of vertex. At last, the contour was detected and the features line was drawn to complete line graph of the cultural relics. This method not only has low requirements for the primitive model but also own flexible perspectives and a high usability, it can significantly improve the efficiency of archaeological drawing.