In order to improve the photovoltaic capacity of microgrid and tap the flexible potential of load end new balance resources, a differentiated aggregation method based on improved isomorphic polyhedron was proposed. The operation constraints of flexible resources such as energy storage, temperature control load and so on are uniformly represented as linear polytopes. After regular grouping, the inner approximation aggregation is realized through the scaling and translation of the benchmark isomorphic polytopes; According to the characteristics of photovoltaic high noon power generation, the time differential weight is introduced to strengthen the regulation ability of the core time period, and the day ahead optimization model of microgrid with photovoltaic consumption as the guidance and minimum operation cost as the goal is constructed. The simulation results show that the proposed method can accurately characterize the polymerization flexibility, significantly improve the PV consumption level, stabilize the output fluctuation, and the scheduling feasibility and calculation efficiency meet the engineering requirements, providing an efficient solution for the large-scale load side resource support of new energy consumption in the microgrid.