NO gas emission has harmfully impacted human health and the environment. Absorption of NO gas into an aqueous solution is considered to be a promising approach for its removal. Fe-II(EDTA) solution has been demonstrated as an efficient option in the denitrification process. However, its absorption rate is strongly affected by mass transfer limitation of NO into Fe-II(EDTA) solution in traditional reactors. In this paper, the removal process of NO with Fe-II(EDTA) solution was studied in a microporous tube-in-tube microchannel reactor (MTMCR). The effects of design and operating parameters such as micropore size, annular channel width, liquid flow rate, gas flow rate, gas-liquid ratio, pH and concentration of absorbent, and absorption temperature on overall volumetric mass transfer coefficient (K(L)a) and NO removal efficiency were explored. The results indicated that the MTMCR exhibited obvious advantages owing to continuous operation mode and higher NO removal efficiency of over 90 %, as compared to traditional reactors. Both K(L)a and NO removal efficiency increased with increases of absorbent concentration and liquid flow rate, as well as decreases of absorption temperature, micropore size, and annular channel width. In addition, K(L)a increased while NO removal efficiency decreased with increasing gas-liquid ratio and gas flow rate. The obtained results imply a great potential of the MTMCR in the removal of NO from post-combustion flue gas.