To address the issues of reverse overload, three-phase imbalance, and overvoltage in low-voltage distribution areas caused by the access of high-proportion distributed photovoltaics, and to achieve the maximization of photovoltaic absorption while ensuring the safe, stable, and economical operation of the power grid. This paper constructs the primary topology and communication control architecture of a multi-distribution area flexible mutual aid system, fully considering the power constraints of the grid and equipment, and proposes a flexible control model for the distribution area mutual aid system. For the high-proportion access of distributed photovoltaics to the distribution network, a model predictive control strategy for load balancing and load transfer supply is proposed. To verify the correctness and effectiveness of the proposed strategy, this paper uses the MATLAB full-time digital simulation platform to build a simulation model of a three-distribution area interconnection system. The simulation results have verified that the proposed control strategy can achieve power regulation in multiple distribution areas and improve the photovoltaic absorption rate under various constraints of grid safety and equipment operation safety.