3D computer modeling is the most important procedure in the reservoir fine description, It can help us to study the reservoir with quantitative and three-dimensional methods. This paper presents an example of the application 3D modeling to the first sand set of the upper ES2 reservoir in the south region of Pucheng Oilfield. Based on the basic data of the strata and structure, faults and structure model are built to display the 3D structure characteristics of the reservoir. The sedimentary microfacies data is imported and analyzed in the software and the variogram is defined to build the microfacies model. And then facies controlled petrophysical modeling technology is used when building the petrophysical model. Finally, In order to examine the precision of the built 3D geological model, according to the fluid model, the geological reserves of each zone is calculated, result manifests that the trueness error is reasonable, and the exported 3D model can be used in the numerical simulation.