Aiming at the problem that the room name and room number (ID) cannot be displayed in the 3D view of Revit model, a middleware is designed to automatically label room information in Revit 3D model. This method uses object-oriented C# programming language and Revit API extension method. Firstly, the building components of each floor plan of Revit model are identified and the room coordinate data information is extracted. Combining SQL server, BIM database (Epplus library) is established to store the extracted data information. Finally, using Visual Studio and Revit platform, coordinate data matching method is adopted to realize automatic annotation of room information of Revit 3D model. The example simulation proves that the method can automatically and accurately locate and identify rooms in Revit model, complete labeling, and improve the work efficiency of designers and drawing examiners.