<p>This study presents numerical simulations of the Klein–Gordon–Zakharov (KGZ) equations, a system of coupled nonlinear partial differential equations, focusing on a discrete non-standard finite difference scheme for the space and time variables. A conservative finite difference method, enhanced by the scalar auxiliary variable (SAV) technique, is developed to handle the discretization. This approach ensures that both spatial and temporal variables are treated in a manner that respects the underlying physics of the equations. We compute the <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\( L^\infty \)</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>L</mi> <mi>∞</mi> </msup> </math></EquationSource> </InlineEquation> error norm for several test cases to rigorously assess the accuracy of the proposed method. By preserving modified energy quantities, the scheme maintains the stability of the numerical solution over time, a crucial property for long-term simulations. Furthermore, its computational efficiency makes it particularly well-suited for large-scale numerical experiments. Numerical examples illustrate the method’s accuracy, computational efficiency, and energy stability. These examples highlight the robustness and versatility of the discrete non-standard finite difference scheme in solving the KGZ equations, offering a reliable framework for exploring complex nonlinear dynamics governed by these equations.</p>