The invention provides an automatic control system of a power station and belongs to the technical field of control methods, which particularly relates to an automatic control system of a power station. The automatic control system of the power station is good in performance. According to the technical scheme of the invention, firstly, when a standby generating set meets a starting condition to be automatically started, a starting successful/failed signal is sent to a CPU. After that, the preparation is made for putting the generating set into use or conducting relevant measures. Secondly, the parallel operation condition is detected and the frequency is pre-adjusted. The switching-on moment is captured. Third ly, the frequency of a power grid is kept at a rated value. When the frequency deviates from the rated value, the frequency is adjusted to be fe. Therefore, the parallel operation is enabled and the active power is allocated. Fourthly, in the light-load condition of the parallel generating set, the active power of a to-be-disconnected generating set is transferred to a currently running generating set. After that, the switching-off operation is conducted. Therefore, no large load is input, and the to-be-disconnected generating set is shut down. Fifthly, the running parameters of the power station are monitored. Meanwhile, the phenomena of reverse power, under voltage and over current during the running process of the generating set can be protected and alarmed.