The investment casting method can save a lot of machine tools and processing time, and greatly save metal raw materials. Its characteristics are that it can cast complex metal castings of various alloys, especially high-temperature textile castings. When pressing the investment mold, the mold with high surface finish is used, so the surface finish of the investment mold is also relatively high. In addition, the mold shell is made of the refractory coating prepared by the special high-temperature resistant binder and refractory material, which is hung on the investment mold, and the surface finish of the cavity in direct contact with the molten metal is high. Therefore, the surface finish of the investment casting is higher than that of the general casting, Generally, it can reach ra.1.6 ~ 3.2 μ M. the dimensional accuracy of investment casting is relatively high, generally it can reach ct4-6 (CT10 ~ 13 for sand casting and CT5 ~ 7 for die casting). Of course, due to the complex process of investment casting, there are many factors that affect the dimensional accuracy of casting, such as the shrinkage of mold material, the deformation of investment mold, the linear change of mold shell during the heating and cooling process, The shrinkage of the alloy and the deformation of the casting in the solidification process, so the dimensional accuracy of the common investment casting is higher, but its consistency still needs to be improved (in use, the dimensional consistency of the high temperature wax casting needs to be improved a lot).