The invention relates to a method for simplifying large-scale virtual dynamic group in the technical field of virtual reality technique. With the purpose of improving rendering speed and rendering effect of large-scale group animation, in the method of the invention, fixed grid surface spot sampling is employed and sampling point redundancy is removed to reduce information memory space, improve pre-processing speed; information retained at a sampling point list and a triangle list is used for replacing vertex information and surface information in an X file of an original model to generate X-file-like files instead of using key frame technology, so that processing complexity of group animation is simplified, different X-file-like files are created according to different LOD levels for group rendering, as a result, rendering speed is accelerated and rendering effect is improved. On the basis, the method of the invention can be employed to effective simplify the large-scale virtual dynamic group.