Abstract: In order to study the influence of the support system of inclined column in the whole construction process of ancient site protection building and ensure the construction safety of Dongduo building in Luoyang Yingtianmen site, a three-dimensional finite element model of Dongduo building was established by MIDAS Gen. Considering the earth pressure, deadweight and construction load, according to the order of design and construction, the simulation analysis of the whole construction process was carried out, and the variation law of stress and deformation of inclined column bracing system during construction was studied. The analysis of the measured and calculated results showed that the influence of the original soil load on the site could not be ignored, the model considering its effect was relatively reasonable, the simulation results were close to the measured results, and the stress and deformation trends of the inclined column bracing system were basically the same. It was suggested to optimize the analysis procedure of pile-soil interaction.