With the rapid development of three-dimentional technologies， geometric and illumination consistency play an important role in the realistic rendering of virtual objects superimposed on real scenes. In order to construct the coordinate measurement system of real and virtual scenes of a stereo camera， realize the geometric and illumination consistency in real fusion， and improve the realism of virtual-real fusion， a geometric consistency virtual-real fusion method was proposed. At transformation from three to two-dimensional space was used for detailed calculation of the geometric relationship between a virtual object and real scene. Following this， a two-dimensional affine transformation was applied to process the two-dimensional images for a more accurate calculation. Finally， combined with the illumination consistency estimation， the virtual object was accurately inserted into the real scene using the differential rendering method to realize virtual-real fusion. The experimental results show that the virtual object can be fused into the real scene completely in terms of size and volume. The geometric consistency after fusion is increased by more than 15%. This verifies the effectiveness of the method and lays a foundation for applications of augmented reality.