In order to solve the state control problems of the train automatic speed control system, improve the efficiency of the train automatic speed-control and reduce the state switching transition, a kind of train automatic speed control algorithm has been proposed. Based on the fuzzy-predictive control logic, use the formal method, design the state control mechanism, and build the automatic speed-control system model. Using anti-interference design, the data analysis and the simulation test have been accomplished. And the results show that the algorithm is feasible.