The invention relates to a casting three-dimensional process designing method which solves the problems caused when the two-dimensional mode is adopted for the existing casting process. Firstly, a casting three-dimensional process designing system which can have the three-dimensional manufacturing reception capacity is designed and is then integrated with a CAD modeling system and a process simulation analysis system; in a system formed through integration, three-dimensional design data issued by a design department are firstly received from a design data management system, compiling is conducted on the basis of the design data, a casting blank model is generated, an appropriate rigging system is selected from a rigging system library for assembling, a rigging system is recreated and kept into a knowledge base if no appropriate rigging system exists, manufacturing parameters, manufacturing process resources and the like are designed, simulation analysis is started on a simulation interface under the analogue simulation conditions, the simulation result is analyzed, the process and manufacturing parameters are optimized, the process is determined, and a visual three-dimensional process is formed. By means of the casting three-dimensional process designing method, the process design efficiency is improved, and the cycle of process development is shortened.