Cutting temperature is one of the most important parameters in the cutting process, which has an important influence on the machining accuracy of workpiece, the power consumed by the machining and the degree of tool wear. There are many factors influencing the cutting temperature, such as the properties of workpiece materials, geometric parameters of the tool, the use of cutting fluid and so on. In this paper, we used orthogonal experimental method, with titanium alloy TC18 as the carrier and AdvantEdge as the simulation platform, established the cutting simulation model. With the cutting temperature as the optimization goal, the geometric parameters of the cemented carbide reamer are optimized.