Control algorithms of automatic train operation (ATO) system are studied in this paper. The characteristics of the
train traction and the single phase of speed adjustment during the train braking are introduced. A fuzzy-PID soft switching control algorithm is then proposed to the ATO system, where fuzzy rules are used to realize the switching between fuzzy and PID controllers. Simulation results show that, the speed control algorithm is efficiency, which improves many functions during the operation of train, such as efficiency, punctuality, energy-economizing, stop precision, riding comfort and so on.