NOVELTY - A process for co-producing synthetic gas through coke dry quenching (CDQ), comprises lifting process in the cooling section, absorbing the heat of the hot coke and increasing temperature, and reacting with hot coke through the heat absorbing chemical reaction to generate the synthetic gas comprising carbon monoxide (CO), carbon dioxide (CO2), and hydrogen gas (H2); where the low pressure steam or the mixture gas of the low pressure steam and the coke oven gas is used as the cooling air, and it is upwards sprayed out from the bottom of the cooling section of the CDQ oven (1).    USE - The process is useful for co-producing synthetic gas through coke dry quenching (claimed).    DETAILED DESCRIPTION - A process for co-producing synthetic gas through coke dry quenching (CDQ), comprises lifting process in the cooling section, absorbing the heat of the hot coke and increasing temperature, and reacting with hot coke through the heat absorbing chemical reaction to generate the synthetic gas comprising carbon monoxide (CO), carbon dioxide (CO2), and hydrogen gas (H2); where the low pressure steam or the mixture gas of the low pressure steam and the coke oven gas is used as the cooling air, and it is upwards sprayed out from the bottom of the cooling section of the CDQ oven (1); the synthetic gas can be discharged from upper part of the cooling section; the gas can be delivered to the steam waste heat boiler (3) and the low pressure steam waste heat boiler (4) to recycle the heat in turn and can be output, after being removed the dust; the overheat steam waste heat boiler can produce the overheat steam; the low pressure steam waste heat boiler can produce the low pressure steam; the low pressure steam is guided into the CDQ oven as the cooling air of CDQ independently or mixed with the coke oven gas or the synthetic gas can be discharged from the upper part of the cooling section; and the overheat steam waste heat boiler can produce the overheat steam and the overheat steam can be used in the backpressure turbine to generate electricity.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of the overall system for co-producing synthetic gas through coke dry quenching.    Coke dry quenching oven (1)    Overheat steam waste heat boiler (3)    Low pressure steam waste heat boiler (4)