This article proposes a method for determining the scale and location of Distributed Photovoltaic (DPV)under the operational constraints of low-voltage transformer areas. Firstly, a low-voltage transformer areas operation model and a DPV output model were established. Determine the access nodes and rated capacity of the DPV using the indicators of minimizing voltage fluctuations and minimizing line loss rate in the optimized configuration model; Then, the maximum capacity of DPV that can be installed in the transformer area is determined with the goal of maximizing the photovoltaic penetration rate in DPV accessible nodes; Use Marine Predators Algorithm(MPA) to solve nonlinear problems in the model. Finally, simulation analysis was conducted using an actual low-voltage transformer area as an example to demonstrate the effectiveness of the proposed model and method, ensuring the safe and stable operation of the low-voltage transformer area when connected to a high proportion of photovoltaic energy.