Abstract: In this paper, the plug-in development method is adopted, which aims to solve that Revit cannot satisfy the domestic standard in quantity calculation during the decoration process. Based on Revit, it made secondary development to study and practice the quantity calculation of decoration. It realized the 3D quantity calculation of decoration through the integrated platform of research and development of modelling and quantification. Thus, it has improved the efficiencies and accuracies of the decoration quantity calculation.