China, an oil and NG scarcity country, is coal dependent, and this situation will remain for a long time. DME, as an ideal replacer of liquid fuel, is considered to develop. The efficient way of producing DME from coal is under research. Considering the components of coal and natural gas (NG), we choose co-feed (coal and NG) and co-production (electricity and DME) system (Co–Co system) to be studied on. Three systems which are the standalone system, co-generation system and Co–Co system are simulated by Aspen-Plus. The simulation results concerning material flows, exergy flows, CO2 emission and the evaluation indexes are obtained. It is found that Co–Co system has higher exergy efficiency, higher economic benefit, and it is environmental friendly because of releasing the least CO2.The analysis llustrates that Co–Co system has obviously advantage over the other two kinds of systems.