Abstract: In computational electromagnetics, the discontinuous Galerkin method is a widely adopted and effective approach for handling non-conformal meshes, offering significant flexibility in addressing challenges posed by complex geometries. Historically, the integral equation discontinuous Galerkin (IEDG) method required additional stabilization terms. increasing algorithmic complexity. Recently, a simplified discontinuous Galerkin (SDG) method has emerged that eliminates the need for stabilization terms while effectively processing non-conformal meshes and maintaining high computational accuracy. This study systematically classifies flawed non-conformal meshes encountered in non-conformal discretization scenarios, and further investigates the adaptability of the SDG method to various types of flawed non-conformal meshes. The impact of mesh imperfections on computational results is evaluated from the illustrative example, and the accuracy variation of the SDG method under different flawed conditions is identified. The performance of SDG under varying mesh conditions is comprehensively discussed, providing a reference for non-conformal grid modeling and electromagnetic scattering accuracy assessment of complex engineering targets.