本文利用有限元素軟體Deform-3D進行旋轉鍛造傘形齒輪模擬分析,研究設計參數對下模具的磨耗深度、應變均勻度與最大磨耗位置點的影響,並利用下模具的最大磨耗深度估計模具壽命。本文之設計參數包含對胚料預成形之參數設計及旋轉鍛造加工製程參數等六個因子。胚料預成形設計參數包含體積V、胚料下端高度h_1、胚料上端直徑d_1以及胚料下端直徑d_2;旋轉鍛造加工製程參數包含下模每轉進給率S以及上模具傾斜角γ。實驗設計採用適合建構二階反應曲面之Box-Behnken 6因子3水準的設計建立共49組模擬,並使用統計軟體Minitab依Deform-3D有限元素分析的結果進行回歸分析,透過回歸分析建立二階多項式預測模型,求得下模具的磨耗深度在良好的情形下,應變均勻度最小之最佳化解。本文所建立的磨耗深度及應變均勻度預測方程式與有限元素模擬的結果進行驗證,其結果顯示預測模型具有精確度。;An ideal FE model of cold rotary forging of a spur bevel gear is developed under the Deform-3D software and the Bottom Die of Life on maximum wear depth and equivalent strain uniformity are in this study. The six factors in the design include the work-piece geometry and the rotary forging process parameters. The work-piece geometry such us piece volume V, Lower height〖 h〗_1, the diameter of the upper and lower diameter〖 d〗_1 〖、d〗_2 and the rotary forging process parameter such us the process parameter with feed amount of per revolution S , and inclination angle of the upper die γ.The experiment adopts 49 groups of analogs with the Box-Behnken design. Use the Minitab software to do the regression analysis and develop the predicted equations. By doing so, it’s excepted using the FEM model and surface response methodology to find the optimum design of the Bottom Die maximum wear depth and equivalent strain uniformity . In this paper Bottom Die maximum wear depth and strain uniformity prediction equation established with the results of finite element simulations to verify the results show the prediction model with considerable accuracy.