Purpose of this research is to investigate the heat source in steady MHD fluid flow under convective boundary conditions, as it moves through a stretched cylinder with changing thermal characteristics. This study holds substantial importance for the oil, gas, and manufacturing industries. This paper examines the similarity transformation approximate analysis of heat transfer in stretched cylinder within porous media, assuming a variable surface temperature. The momentum and energy PDEs are converted into strongly nonlinear ODEs using similarity transformation, and approximate analytical solutions are derived via the Homotopy Analysis Method. The study indicates that as permeability of porous media and magnetic parameter increase, the flow velocity decreases, temperature rises, and thermal boundary-layer thickness diminishes with a higher Prandtl number.