Abstract: The ratchet wheel made of ZL114A aluminum alloy in high-speed railway has many problems such as heavy weight and numerous defects.In order to obtain high-quality and lightweight ratchet products, the structure and casting technology of the existing ratchet were studied.The defective position of the ratchet wheel was obtained by nondestructive testing.The filling and solidification process of the ratchet wheel in low-pressure casting were simulated by the software ProCAST, and the location of possible shrinkage cavity and porosity in the ratchet wheel was predicted.The casting process was improved by adding a water cooling system at the spoke and large wheel positions of the ratchet and increasing the pressure pressure.The results of force analysis and flow analysis show that, the weight loss ratio of the optimized ratchet reaches 18.8%.The ratchet is safe under working load and damage load, its safety factor meets the requirements of safe use.After improving the casting technology of the ratchet wheel, the filling is stable without turbulence phenomenon, and the molten metal shows sequential solidification, which effectively avoids the defects such as shrinkage cavity, porosity, and oxidation slag, and, high-quality ratchet castings can be obtained.