In this work, the steady state design of ethylene glycol (EG) production process by the dimethyl oxalate (DMO) hydrogenation is investigated. In comparison with the conventional ethylene oxide hydration process for EG production, this novel process provides better conversion and selectivity. The DMO hydrogenation process is comprised of a reaction section and a sequence of distillation columns as separation section. In reaction section, DMO is dissolved in methanol, and this DMO solution is then reacted with hydrogen to become EG and side products. Then, the raw product stream is fed into the sequence of distillation columns to, obtain the EG product stream at the specified purity. After the initial process design is completed, the DMO hydrogenation process is optimized to obtain the optimal design with the minimum total annual cost (TAC). During process optimization, it is found that the mole ratio of hydrogen to DMO (HDMR) has global influences on TAC, and thus it is the last variable to be optimized. In this paper, the optimal case with HDMR= 40 is obtained through optimization. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.