Abstract: To explore the high-speed railway block section partitioning method applicable to the CTCS-3 level train operation control system, this paper analyzed the factors affecting block section partitioning, constructed a multi-objective strategy based CTCS-3 level high-speed railway block section partitioning model, on the premise of ensuring the safety of train operation, used particle swarm optimization algorithm to solve the model, and optimized the fitness function in the algorithm. The case study on the Tengzhou East - Zaozhuang section of the Beijing Shanghai high-speed railway shows that the optimization method proposed in this paper can effectively shorten the train running interval and has practical significance for the design of high-speed railway block section.