Current sharing method and device for power supply system, and power supply system

Embodiments of the invention provide a current sharing method and device for a power supply system, and a power supply system, to solve the problem that the existing current sharing technology cannot achieve the purpose of system energy saving optimization in some application environments. The method includes that: a first power system receives desired current percentages of power systems of various attributes in a power supply system, wherein the desired current percentages of the power systems of various attributes in the power supply system are determined by preset load sharing percentages of the power systems of various attributes; the first power system determines whether in an on state; the first power system determines the desired current percentage of the first power system according to the self attribute and the desired current percentages of the power systems of various attributes; the product of the desired current percentage of the first power system and the rated current thereof is taken as the d