NOVELTY - Transferring carbon dioxide in exhaust gas into natural gas includes transforming or rectifying surplus electricity, and charging it to electrolyte solution; purifying the industrial flue gas, and purifying the captured carbon dioxide; transferring the hydrogen and the carbon dioxide; performing indirect heat exchanging treatment; inputting the overheated vapor to a turbine generator to work; returning the generated electricity transforming or rectifying step; continuously using it to electrolyze water; and condensing and drying the mixed gas.    USE - Method for transferring carbon dioxide in exhaust gas into natural gas (claimed).    ADVANTAGE - The method solves the problems that the renewable energy cannot be stored when the network is trapped in failure or in short time, and the electricity generated by fossil energy has greenhouse gases which pollute the environment. The renewable energy and the carbon dioxide waste gas can be used.    DETAILED DESCRIPTION - Transferring carbon dioxide in exhaust gas into natural gas comprises:    (A) transforming or rectifying surplus electricity which is generated by the renewable energy and cannot be stored or has disorder net, and charging it to electrolyte solution, where the water after electrolysis is separated into hydrogen (H2) and oxygen (O2); and the water in the H2 is completely cleared up;    (B) purifying the industrial flue gas so the carbon dioxide (CO2) is separated, and purifying the captured CO2;    (C) transferring the H2 generated in step (A) and the CO2 captured in the step (B) to a synthesis device which comprises two stages of fixed bed reactors (11, 13) such that the methane strong exothermic reaction can be finished by action of catalyst, to generate high-temperature mixed gas with main components of methane (CH4) and steam;    (D) performing indirect heat exchanging treatment for the technique water by the high-temperature mixed gas generated in the step (C) so that the technique water is transferred as overheated vapor;    (E) inputting the overheated vapor generated in the step (D) to a turbine generator (4) to work; returning the generated electricity to the step (A) to transform and rectify; continuously using it to electrolyze water; and    (F) condensing and drying the mixed gas in step (D) after heat exchanging and temperature reduction until the natural gas whose CH4 content meets the standard.    An INDEPENDENT CLAIM is included for a device for transferring carbon dioxide in exhaust gas into natural gas, comprising transformation and rectification device (1), an electrolytic tank (2), a steam generator, and a carbon dioxide heater (21).    DESCRIPTION OF DRAWING(S) - The drawing is a schematic diagram of a device for transferring carbon dioxide in exhaust gas into natural gas.    Transformation and rectification device (1)    Electrolytic tank (2)    Turbine generator (4)    Fixed bed reactors (11, 13)    Carbon dioxide heater (21)