Abstract: In the wireless local area network(LAN) bandwidth allocation system for the passenger train, the link discovery module was used to balance the load of 9 road links, jhash_3words algorithm and Round Robins algorithm were used to construct the discovery module, update the number of real users in the system in real time. The system optimized the mode of bandwidth allocation, could effectively enhance the efficiency in the use of the Internet. The system passed the performance test and the function test of the national railway product quality supervision and inspection center. It laid a solid foundation for the practical application in the high-speed train.