A 3D point cloud dataset of the Terra-cotta Warriors was built by 3D laser scanning, and then a high-precision 3D solid mesh model was established with the assistance of Geomagic Studio and Hypermesh. Using the finite element method (FEM) simulation in the ankles of Terra-cotta Warriors, characteristics of Von Mises stress and deformation were investigated to determine the vulnerable parts of the ankle. The optimal proportion of the points simplified on each fragment was confirmed and applied to FEM simulation with the same condition as the original model, to verify the reliability of simplification. The results show that the whole structure can remain safe and stable under gravity, as the vulnerable part is in the left ankle. For most fragments, the optimal proportion is 60%~70%, which can effectively reduce the modeling time. The error of Von Mises stress in the points-simplified model is less than 15% compared with that of the original model. The stress contour and deformation pattern are also comparable with the original results, which means the process of points simplification can provide comparatively accurate results and save time.