Micro combustor is one of the most important components in a micro-thermo-photovoltaic (MTP) system. A high and uniform temperature distribution along the outer surface of the combustion chamber is necessary to ensure a high radiation power density. At different air flowrates of admixture of hydrogen and oxygen, the temperature distributions both along the wall and on the exit plane of micro combustor were obtained through the experiment of the micro combustor with a sudden step. The experimental results indicated by that the position of flame center could be completely controlled in the combustor with a sudden step; steady temperature distribution could be obtained along the outer wall; and whirlpool could be brought on the sudden step, to enhance the mix of hydrogen and oxygen.