Abstract: CO2-CH4 reforming by non-equilibrium plasma to syngas is an important emerging technology pathway to realize the resource utilization for the two greenhouse gases. The reaction pathway of CO2-CH4 reforming by non-thermal plasma in a dielectric barrier discharge (DBD) reactor at ambient temperature and pressure was thoroughly investigated by combing emission spectrometry analysis, reaction kinetics simulation and continuous mass spectrometry measurements. A maximum conversion of CH4 and CO2 of 25.8% and 9.6% respectively, can be achieved under a specific energy input (SEI) of 52 J/cm3. The continuous mass spectrometry online analysis of the stable gaseous products shows that C2H4 acts as a key intermediate in the formation of C2 hydrocarbons. The higher the proportion of CH4, the greater the generation of C2 hydrocarbons, and it increases in the order of C2H6