With the shortage of petroleum，liquid fuel techniques are needed to reconstruct a reliable energy framework.To solve the problem with the greenhouse gases in utilization of fossil fuel，coal based polygeneration is now becoming one of the choices.The application of coal-based polygeneration depends on the conversion of raw material to liquid fuel and decrease in the waste gas to the environment.In this study，process simulation software Aspen Plus was used to setup the module of the polygeneration system based on its mass and energy balances.Coke-oven gas and coal gasified gas were input into the system as the feeding materials，in which methane mainly from the coke-oven gas and CO2 from the coal gasified gas reacted to adjust the ratio H/C in the syngas.The main components of the greenhouse gases (CO2 and CH4) were reduced due to the CH4/CO2 reforming.The simulation includes five units，which are the unit of air separation，gas clean-up unit，reforming，production of chemical products，and combined turbine cycle.The processing units with the chemical reactions were included in the program through the dynamic and thermodynamic subroutines.Dimethyl ether (DME) and electric power are the main products from the simulated polygeneration system.The equivalent electric power efficiency (η1) and total heating efficiency (η2) were calculated.The results showed that η1，which refers to the energy quality，is more appropriate for evaluating the coal-based polygeneration system.