Micro-expression is the real expression of human emotional expression. In the process of animation production, both two-dimensional animation and three-dimensional animation need to simulate the real person’s facial expression as much as possible. Micro expression animation key frame nesting refers to the formation of simulated micro expression graphics on the basis of referring to real micro expression data. The key frame of graphics is inserted twice on the basis of the existing key frame sequence of expression animation, and the facial expression is simulated finely. Based on the data of human facial micro expression database, this paper creates and inserts the key frame data. The experimental results are more vivid than those without inserting the key frame of micro expression. The simulation accuracy of animation is higher and more impressive. This method has certain practical value for improving the effect of two-dimensional animation, three-dimensional animation and VR(i.e., Virtual Reality) simulation of human face animation.