Abstract: A multi-objective optimization method and system for a master production plan of casting parallel workshops belonging to a casting, producing, and scheduling fields are provided. In the method and the system, discrete coding is adopted, and parallel scheduling information is directly converted into discrete particles. Through crossing and mutation of each particle together with non-dominated particles in a global optimal solution set and individual optimal solution sets, a quick search of a solution space is completed. Congestion distances of non-dominated individuals in the solution space are calculated, sorting is performed according to congestion, and a new population is generated to allow the solutions to be uniformly distributed.