Abstract: IFC and CityGML are both semantic models. By analyzing the correlation and difference between BIM and IFC model information and components in CityGML, information is filtered and extracted, semantic mapping transformation is established, and data information between them is transferred to realize data interconnection and seamless connection between BIM model and multi-source GIS data, so as to achieve deep integration of BIM and GIS. The integration of BIM and GIS requires lossless transmission and transformation of model information, and GIS data transformation can keep almost complete information such as coding and attributes of BIM data. The data converted by GIS can be stored centrally, and the model with complex structure and huge volume can be opened, roamed, queried and analyzed quickly. It also has a comprehensive authority management mechanism, which can not only completely preserve the hierarchical structure of data in BIM software (architecture, structure, electromechanical system, etc.), but also not lose its own parameters, colors and attribute information of model single data.