A method for driving an OLED panel includes the following steps. An image signal is inputted to a power control unit, wherein the power control unit includes a calculator and a power control look-up table. A display loading ratio is calculated by the calculator according to the image signal, wherein the power control unit can find an emitting time ratio by the power control look-up table corresponding to the display loading ratio, the emitting time ratio can be transformed to an emitting time signal, and the emitting time signal can be inputted to the OLED panel so as to control the power consumption of the OLED panel.