An investigation on non-premixed H-2/air combustion in a cylindrical micro combustor has been carried out. The effects of porous media and outer wall thickness on the combustion characteristics, flame location, thermal performance and energy conversion efficiency of the thermo photovoltaic (TPV) system were investigated. For the application of micro TPV system, a high and uniform outer wall temperature distribution is indispensable for the sustaining output, and the high energy efficiency is desirable. The results indicate that the setting of porous media or the increase of outer wall thickness can enhance the heat transfer in micro combustor and affects the flame stability, and the micro combustor with porous media and outer wall thickness b = 0.2 mm obtains the lowest flame location. They are also conducive to the improvement of outer wall temperature and energy efficiency, the outer wall temperature of the micro combustor with a thicker outer wall and porous media is relatively uniform and the energy conversion efficiency of micro TPV system is also improved, the micro combustor with b = 0.6 mm and porous media is more suitable for the application of micro TPV system. Additionally, the external thermal environment also can improve the outer wall temperature profile and the working performance of the micro combustor.