This study focuses on the intelligent fusion application of BIM and GIS in construction engineering. Through the practical design of the coordinate system unification

model lightweight and multi-source data linkage technology

the fusion technology significantly improves the engineering construction precision and efficiency and quality compliance

reduces the occurrence of safety accidents

and effectively reduces the comprehensive cost. The conclusion confirms that the integration of BIM and GIS is the core path to break through the technical bottleneck and realize the dynamic monitoring and intelligent management of the whole project area

which provides a replicable practical path and scientific integration method for complex construction projects.