An embodiment provides a method, a device, and a system for obtaining sharing power, and relates to the field of communication. The method, the device, and the system can improve use ratio of power resources, and reduces waste of power resource. The method comprises: a network side device obtaining transmitting power of each carrier wave in a first cell; the network side device adjusting the carrier wave whose transmitting power is highest in unadjusted carrier waves to a power amplifier whose power is highest in power amplifiers in the first cell; the network side device updating available power of the power amplifier whose available power is highest; the network side device repeatedly executing the adjusting and updating steps until all carrier waves in each carrier wave are adjusted; and the network side device obtaining minimum values of the available power of each power amplifier as a sharable power of the first cell. The method, the device, and the system provided by the embodiment are used for power sharing.