As the most significant element of the three main materials of building construction, reinforcement is the main concern of cost and quality control in construction project. However, the existing reinforcement blanking work is basically completed by manual lofting in China, and it is extremely dependent on the technical experience of the construction site. Taking the work flow of steel bar blanking as the main line, this paper upholds the three scoring principles: structural safety, convenient construction and economic saving. What's more, combining with the specification of steel bar atlas and construction habits, this paper makes secondary development on Revit software with the help of graphic geometry algorithm, calculates the steel bar blanking of columns, walls, beams and slabs, etc., and further carries out various ways of steel bar layout rehearsal with preset programs. Moreover, the best is scored according to the results of reinforcement arrangement so as to find the optimal solution of reinforcement blanking, and the relevant calculation data are stored in the form of external database files. This paper takes Nanjing public security building as a case to practice and test the stability of the algorithm. And its results show that it can succeed in saving materials and low-carbon construction compared with the traditional reinforcement blanking methods.