The high-precision integrated geological model of large area is the basis and key to deepen the geological characteristics of integrated reservoirs, improve the understanding accuracy of residual oil description and overall development law, and realize the model management and intelligent precision development of oilfields. Currently, there are many problems in the high-precision integrated modeling of large area, such as complex multi-stage fault intersection relationship, difficult accurate characterization of fault spatial morphology, strong heterogeneity of reservoir sand body, low simulation accuracy of thickness and permeability and other properties. To solve these problems, a technical process of integrated geological modeling suitable for the scale of hundreds of layers and thousands of wells was formed, and a precision characterization method of integrated model with “fine correction of fault morphology and fine simulation of reservoir difference” as the core was developed, which realized the transformation of fault morphology from 5-point control to multi-intersection control, and the transformation of attribute simulation from a single variation function to multi-function combination. A high-precision integrated geological model of 24,000 wells, 335 faults and 158 sedimentary units in Sazhong Development Zone was established, with the structural lev el error of 0.31‰, and the overall distribution error of the model is less than 2%. It has achieved the fine modeling accuracy of small blocks, laying a foundation for high-precision numerical simulation of development zone and the study of macro distribution law of residual oil.