Tool passivation asymmetric edge shape factor is one of the important factors affecting the temperature field and stress field. However, the height of the split point，the shear angle and the actual negative cut front angle at the cutting edge change with the change of shape factor, and the temperature field and the stress field are changed under the interaction of each other.The cemented carbide milling tool model with different shape factors was established by using SolidWorks,the simulation model of cutting 45 steel with tool with passivation asymmetric cutting edge was established by using the finite element software AdvantEdge, and the influence law of different shape factors on temperature field and stress field was studied. The results show that with the increase of the shape factor, the maximum cutting temperature increases, while the area of the highest stress field increases first and then decreases.