In order to improve the application of BIM technology in reinforced concrete structure design. Methods: This paper takes the housing project in District A of Guangzhou as the research object, and uses BIM technology to design the precast part of the reinforced concrete structure in the C household, including the deepening design of the reinforced concrete structure, production management of the precast components, tracking, address data modeling, hoisting and deployment, etc., which penetrates into all aspects of the design of the reinforced concrete structure. It was found that after the application of BIM technology, the construction period was reduced from the originally established 13 days per floor to 7 days per floor, and the on-site construction errors were reduced, the construction efficiency and construction quality were improved, and the project was successfully completed. It can be seen that the application of BIM technology in the design of reinforced concrete structures in urban buildings can shorten the construction period and ensure the construction quality at the same time. It is a favorable means to promote the development of urban construction industry and should be actively promoted.