The cutting edge preparation of the tool can be used to remove edge defects and improve tool life and stable cutting performance. The prepared edges are symmetrical or asymmetrical. The modeling software SolidWorks is used to establish the two dimensional(2D) model of the blade with different shape factors. The cutting simulation software Third Wave was used to set up the finite element model(FEM) of the prepared asymmetrical edge of the carbide cemented tool on milling the 45 steel. The prepared asymmetric tool edge shape factor on the distribution law of tool temperature field during cutting process was analyzed and the influence law of asymmetrical edge on cutting temperature was revealed. The research results are of great scientific and engineering significance for realizing the optimization of tool edge preparation and promoting the development of equipment manufacturing industry.