More attentions have been paid to 3D geological modeling by earth science experts and scholars, which gradually becomes a research hotspot in the fields of mine geology, oil and gas exploration, etc. The detailed description of the 3D geological model is the prerequisite and guarantee for metallogenic prediction and reserve estimation,which is more favorable to play an important role in 3D visualization technology and geostatistics. A bauxite deposit in Henan Province was provided as an example and a series of difficult problems were dealt with in the 3D geological modeling. First of all, we used multiple vertical profiles to build ore body contour line. Based on the geological exploration data, the modeling process was discussed. The geometric database raw data format was revised. The auxiliary coil was used to build 3D model. Then, terrain surface model, the 3D ore body model, 3D stratum model and 3D structure model were successfully established. Based on the accurate 3D models, the L1 reserve was estimated by the Distance Power Inverse Ratio method and Ordinary Kriging. Ore bodie distribution and the reserves category were expressed. Finally, three different verification methods were used to verify the accuracy. Based on the traditional modeling method, a method based on the actual spatial location modeling of exploration engineering was improved, which can be modeled by any exploration project location. The accuracy and reliability of modeling were improved. It achieved the goals of the reserves category, reserve grade interval and reserve estimation dynamic visualization. The errors were within the controllable range.