Recently, micro power generation devices based on the micro combustion process have been extensively stimulated by the persistent breakthrough of MEMS techniques. As a major component, the design of a micro combustor is very critical when determining the power output of these devices. In this paper, a new type of micro planar combustor for micro thermophotovoltaic system is proposed, which has multi-mode heat transfer passages in the combustion channel. A three-dimensional CFD model with a skeletal reaction mechanism embedded is established for premixed hydrogen-air combustion in the micro combustor. Simulation studies are conducted to investigate the basic combustion characteristics and the effect of structure parameters on the combustion processes. It is found that compared to single-passage combustor, the new combustor can achieve a higher mean temperature of the radiation wall due to the enhancement of heat transfer, and it becomes more obvious with the increase of plate number. The length of heat transfer passage also significantly affects the average value and uniformity of the external wall temperature distribution. Some useful designing parameters have been obtained so as to give a reference for the similar combustor. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.