The purpose of this project is to conserve large-scale historical subjects in digit form. A long-range laser scanner is applied to record the boundaries of buildings . Scanned point clouds are converted into 3D computer models, sections, and boundary projections. The digit models are used as the references for chronicle record and comparison. This project chooses Pao-An Temple's main hall, roof ridge, wood structure, dragon column, and a hanging decorative component to work with. It is expected to achieve a two-way construction process, integrate geometric and image data, and establish a digit reservation working process.