The invention discloses a reduction quantity distribution method under an AHP model in a power system and relates to a reduction quantity index distribution method of a grid side of a power system. Distribution of reduction quantity indexes between a grid side and a distribution station in demand response is realized and real-time index updating is supported. According to the embodiment of the invention, a reduction quantity index distribution strategy method of a power system is provided. The distribution method is characterized in that on the basis of an analytic hierarchy process (AHP) model, reduction distribution important degrees between multiple target distribution stations are distinguished according to set factors, like a user type and a user load type, in the model; and different distribution station weighs are provided and reduction quantity indexes are distributed; and the divided indexes are issued to different distribution stations.