Abstract: In this paper, an efficient Shooting and Bouncing Rays (SBR) based computational method is proposed to address the rapid electromagnetic scattering computation of electrically large targets coated with radar-absorbing material. Using the Generalized Propagation Matrix method, the reflection coefficient of multi-layer dielectrics with a metallic substrate is derived, which is subsequently coupled with the Shooting and Bouncing Rays method to accurately calculate the radar cross section of complex targets coated with multi-layer dielectric materials. To further improve computational efficiency, MPI parallel acceleration technology based on CPU platforms is employed to reduce computation time, resulting in high parallel efficiency for the SBR method. Numerical results show that the calculated RCS of the dihedral corner reflector and ship models agree well with FEKO results, with the reflector's RMSE below 3 dBsm. Additionally, for electrically large coated aircraft targets, the parallel efficiency exceeds 80%, demonstrating the method's accuracy and efficiency.This method effectively solves the accuracy and speed issues in the electromagnetic scattering computation of coated large-scale targets, providing an efficient solution for the stealth performance evaluation of complex large-scale targets.