Method and system for solving optical scattering field by finite element of compression calculation area

The invention provides a method and system for solving an optical scattered field by a finite element of a compression calculation region, and belongs to the technical field of compression, and the method comprises the steps: segmenting an initial target finite element calculation region into two sub-regions by taking a mirror symmetry axis as a segmentation line according to the mirror symmetry of an optical device, selecting one of the sub-regions as a compressed target finite element calculation region; the method comprises the following steps: decomposing an incident field into two sub-incident fields by using mirror symmetry, converting scattering field solving into two sub-scattering field solving, and adding a boundary condition for each sub-scattering field solving; on the compressed target finite element calculation area, the sub-incident fields serve as new incident excitation calculation sub-scattered fields, and the two sub-scattered fields are overlapped to serve as an optical device scattered fi