3D reconstruction plays an essential role in the documentation and protection of ancient architecture. 3D reconstruction and photogrammetry are mainly used to conserve the datum and restore the 3D model of large-scale ancient architecture in our work. The whole procedure and an algorithm on space polyhedron are investigated in this paper. Firstly lots of conspicuous feature points are laid around the huge granite in order to construct a local and temporary 3D controlling field with sufficiently high precision. And feature points on the granite are obtained by means of photogrammetry. We use DLT (Direct Linear Transform) to calculate coordinates of feature points and accuracy evaluation of all feature points can be obtained simultaneously. A new generation algorithm for spatial convex polyhedron is presented and realized efficiently in our research. And we can get 3D model of the granite. In order to reduce duplicate storage of points and edges of the model, model connection and optimization are performed to complete the modeling process. Realistic material can be attached to the 3D model in 3DMAX. At last rendering and animation of the 3D model are completed and we got the reconstructive model of the granite. We use the approach mentioned above to realize the 3D reconstruction of large-scale ancient architecture successfully.