This paper proposes a method for extracting channel features in specialized 5G application scenarios, aiming to address the simulation discrepancies in metal aperture-coupled models using the ray tracing algorithm. Simulations performed on a 100 × 100 × 15 cm 3 metal cavity with aperture using both full wave and ray tracing methods revealed distinct differences in field strength distributions. Based on the derived convolution formula, this study presents a more accurate electric field distribution in metal cavity with aperture. Compared to the straightforward ray tracing method, the proposed channel modeling and field strength extraction techniques offer a novel theoretical foundation for electromagnetic wave propagation in enclosed metal scenarios. Within this metal model, the proposed method combines the precision of full wave methods with the efficiency of ray tracing techniques.