A power control system includes a control unit, a motor, an electricity storing unit, and a generator set. The control unit includes a charging/driving controller and a load controller electrically connected to a load. The motor can be driven by electricity of the electricity storing unit. The generator set includes a revolving wheel which is driven by the motor for driving a driving power generator and an energy storage generator. The driving power generator provides electricity to the load. Electrical energy generated by the energy storage generator is used for charging the electricity storing unit. When the generator set breaks down, the electricity of the electricity storing unit is provided to the load through a control of the charging/driving controller. The power control system supplies sufficient electrical energy to the load under low energy consumption condition and has advantages of environment protection and fault alarm.