Base on the analysis on the turbine guide vane and the structure claracteristic of investment model and the tneory of feature mapping, the structure feature, the restriction relationship of inner feature and the geometrical element composing feature are distilled. The die cavity model for the investment casting die design and manufacturing is obtained by adding machining alowance, technical accesories and ratio of shrinkage into inside and outside part model of guide vane. And then the automatic conversion among models of the investment casting die design is realized. This method shortens the design cycle of the investment casting die and has the important value in theory and practical aplication.