In the process of project implementation, due to the multiple impacts of field data information collection, GIS data integration, and the complex level of BIM information technology, the technical route of BIM and GIS lacks applicability and timeliness, resulting in slow progress in the process of land expropriation and demolition in the early stage of the project. The research relies on the Luotian--Tiegang Reservoir water conveyance tunnel project. Based on the key and difficult points of the project, the breakthroughs in smart platform architecture innovation, land acquisition and relocation process sorting, and BIM+GIS acquisition and relocation technology information integration have been made. The application of BIM+GIS technology in land acquisition and relocation planning of the urban core ecosystem has been explored.