Abstract: The route search of computer interlocking system needs to have higher safety and reliability as well as faster search efficiency, to meet the requirements of high-speed railway interlocking system. According to this requirement, the computer interlocking system of high-speed railway was designed by using the route searching algorithm of the binary tree structure. The key part of computer interlocking system that based on binary tree structure was to find signals in plane layout and use them build a binary tree. The mode of binary branch tree was similar to shape of station yard. Node of binary tree and the interlocking device of station were one-to-one correspondence on the relationship between the equipments. Therefore, it was easy to set up binary tree model according to the station yard layout. Binary tree model provides convenient to writing program, at the same time, to the benefit for route search.