The invention discloses a modeling method of a large geological building information model, which comprises the following steps: 1. Acquiring onsite scene data of a work area through tilt photographyand three-dimensional laser scanning technology, and constructing a three-dimensional scene model of the surface of the work area and a data set of point clouds; 2, extract DEM data and obtaining an optimal DEM model by fitting a curved surface; 3, primary drill restrict; 4, secondary terrain constraint; 5, plane geological constraint of the third time; 6, constrain that law of four geological evolution; 7, combine that surface three-dimensional real scene model and the underground three-dimensional geological body model and integrally displaying them to obtain a large geological build information model. The method of the invention is advanced, which combines the underground three-dimensional geological body and the three-dimensional real scene model of the ground surface for display, andhas the advantages of visualization, synergy, operability and the like. The method is Widely used, can effectively improve the management level.