The invention discloses an intelligent turnout aided design system. The aided design system includes a parts graphics library and a knowledge base module, a general layout quick design module, a parts design graphics generation module, a BOM table generation module and a system working area. According to the system, a general layout can be generated according to main design parameters such as turnout number, rail distance, and constraint rules; according to the design parameters, parameterized graphics of switch, frog, guard rail, basic rail, sharp rail are automatically generated; an inference engine based on RETE algorithm is responsible for completing the constraint analysis and constraint solving of turnout key parts; according to the actual use demands, the graphics library is expanded in a customized mode to generate new parts graphics; scheme comparison is conducted according to the preset knowledge base, and the best solution is selected by an expert decision support system. According to the intelligent turnout aided design system, the design cycle of turnout can be shortened, design error is reduced, and indirect overhead is saved.