In order to solve production defects such as shrinkage and porosity inside a certain train coupler casting in Anhui Xinhong Machinery Co.,Ltd., the main reasons of defects are found through the process of CAE simulation analysis and physical X ray detection to determine the location and morphology of casting defects and to reflect the actual situation of coupler filling and solidification process. The main reasons are found as follows: uneven thickness of casting structure, insufficient original gating and feeding system and etc. Through the process optimization and apply multidimensional vibration, then test validation, the train coupler casting which meets the technical requirements has been successfully produced, ensuring the smooth mass production of the company. ProCAST numerical simulation results have confirmed the rationality of the proposed work in optimization process measures in reducing and eliminating the shrinkage defects.