In this paper, the nitration characteristic of alcohols with mixed acid for the synthesis of energetic materials in a stainless steel microreactor was investigated experimentally. The nitration of iso-octanol with HNO3-H2SO4 mixed acid was chosen as a typical model reaction which involved fast and strong exothermic liquid-liquid heterogeneous reaction process. The influences of mixed acid composition, flow rate, organic/aqueous flow ratio and reaction temperature have been investigated. The results indicated that the reaction could be conducted safely and stably in the microreactor at 25-40 degrees C, which are enhanced compared to 15 degrees C or below for safe operating conditions in the conventional reactors. Moreover, the 98.2% conversion of iso-octanol could be obtained and no by-products were detected in all cases.