Abstract: Geological modeling and numerical reservoir simulation are considered as important tools for modern reservoir research and management, and it is of great significance to promote the development and application of modeling and numerical simulation integration technique for efficient exploitation of oil and gas reservoirs. This paper briefly elaborates the formation, development and deep integration of the modeling and numerical simulation disciplines, and also analyzes the connotations of modeling and numerical simulation integration in terms of concept, process, algorithm and application, as well the development trends for key techniques of modeling and numerical simulation integration. At present, geological modeling technique needs to be further explored in terms of seismic multi-information drive, multi-point new statistical algorithm, geological process simulation and artificial intelligence technology; numerical simulation technique should focus more on in-depth studies of multi-phase, multi-component and multi-field coupling, physicochemical porous flow, whole-reservoir integration simulation and AI-based automatic history matching. Main methods for achieving modeling and numerical simulation integration are proposed, including building an integrated software platform, establishing standard procedures and standards, giving play to demonstrative and leading roles and fostering versatile talents. Moreover, it is considered that multi-dimensional and multi-scale data assimilation, construction of big reservoir development model and digital twin will be the future development trends for integrated modeling and numerical simulation.