Abstract: The disclosure provides a method, system and device for controlling power sharing of a cluster of charging piles, comprising calculating a remaining power of the cluster at a current time according a total power upper limit of the cluster at the current time, a total number of charging piles of the cluster at the current time and an actual output power of each charging pile; calculating a weight of each charging pile for distributing the remaining power according to performance state of each charging pile; and obtaining a power output upper limit distributed to each charging pile at the next time according to the remaining power at the current time, the weight and the actual output power of each charging pile. The disclosure automatically adjusts the power output upper limit distributed to each charging pile in real time, thereby improving equipment utilization and load utilization of the charging station.