A numerical formulation with second-order accuracy in the time direction and spectral accuracy in the space variable is proposed for solving a nonlinear high-dimensional Rosenau-Burgers equation. We show how the spectral element method and the two-grid idea can be used together. The two-grid idea is combined with the spectral element method for simulating the nonlinear high-dimensional Rosenau-Burgers' equation. The proposed technique is based on the three-level algorithm. The existence and uniqueness of the solutions to Steps 1, 2, and 3 are investigated and also the error analysis is discussed. © 2023 IMACS.