The invention relates to a low-frequency oscillation disturbance source positioning method considering steady state point time varying. The low-frequency oscillation disturbance source positioning method comprises the steps of extracting network data; constructing an energy function; identifying a stable point; performing energy decomposition and calculation; and judging the location of a oscillation disturbance source. According to the method provided by the invention, decomposition is performed on components contained in the energy function through mathematical derivation, components which are irrelevant to disturbance source positioning, such as state energy and reciprocating oscillation energy, are excluded, and the position of the disturbance source can be judged according to the propagation direction of dissipated energy.