To improve the combustion stability of micro combustor, both sides-slitted bluff body is applied to the micro combustor. The H-2/O-2 reaction mechanism is used to study the influence of controllable slit width (d) and angle of controllable flow (beta) on combustion characteristics of the micro-combustor. The result shows that the reduction of d can significantly improve the combustion efficiency. Under the same controllable flow ratio (gamma), the reduction of d can effectively expand the recirculation region. However, the blow-off limit will be reduced if d is too large or too small. With the same gamma, the recirculation region and low-velocity zone expand when beta decreases, which can entrain more high temperature gas and increase the residence time of fuel in the low-velocity zone, thus improving the combustion efficiency. The residence time of fuel in the combustor will be reduced when beta is too large or small, resulting in lower combustion efficiency and blow-off limit. Therefore, it is significant to choose the parameter of d and beta. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.