Abstract: In view of the high proportion of railway bridges in China, the wide application range of standard components and the heavy workload of span layout, this paper studied the intelligent span layout of bridges by combining building information model with artificial intelligence technology. According to the bridge span arrangement principle, based on the information set, this paper selected the Q-learning algorithm for the secondary development of Bentley platform, and formed a complete set of visual bridge span arrangement scheme. The verification results show that the scheme can be applied to the design of general railway bridges, and improve the application depth and breadth of BIM data from the design level, and improve the efficiency and quality of bridge span layout.