Abstract: Sim-Coupled potential energy principle with the region subdivided into subregions and sAn-coupled finite element method, and generalized sun-coupled potential energy principle with the region subdivided into subregions and generalized sim-coupled finite element method in photoelasticity are established in thes paper. Tile establishments of these sim-coupled potential energy principles with the region subdivided into subregions and the sim-coupled finite element method lay the theoretical foundations for solving the influence of Poisson's ratios on the accuraCy of frozen stress method in photoelasticity and provide the calculation means for transforming the stress fields of models into those of prototypes.