Abstract Fischer-Tropsch (FT) synthesis was carried out in a microchannel reactor using an iron-based catalyst. The performance of microchannel reactor was evaluated in the aspect of CO conversion versus time on stream, catalyst deactivation, pressure drop and gas hour space velocity. The result indicates an excellent mass and heat transfer in the microchannel reactor. The negative impact of external and internal film diffusional limitation could be avoided in this microchannel reactor at experimental conditions. The effect of reaction temperature, operational pressure, syngas ratio and space velocity upon CO conversion and hydrocarbon selectivity were extensively investigated. The kinetic modeling was conducted and the mechanisms i.e. carbide, enlic, alkyl, formate and CO insertion were extensively explored. A mechanism derived from Eley-Rideal-type mechanism was found to be the most statistical and physical relevance at the experimental conditions during FT synthesis using iron-based catalyst in this microchannel reactor.