A model simplification method is provided. The model simplification method includes: constructing a surrounding body to surround a model, wherein the model includes at least one primitive and a plurality of vertexes; drawing the model and the surrounding body to at least one rendering surface by respectively taking each of the plurality of vertexes as an eye-position; determining whether the surrounding body drawn on the rendering surface by taking a current vertex of the plurality of vertexes as the eye-position is occluded to decide whether to mark the current vertex as an invisible vertex; and eliminating a current primitive from the model when all vertexes of the current primitive of the at least one primitive are marked as the invisible vertex.