Using wood chips as carbon source,urea as nitrogen source and KOH as activator,a series of nitrogen-doped biomass carbon CH4-CO2 reforming catalysts were prepared. The structure and properties of fresh and spent catalyst samples were analyzed by surface pore structure analyzer,electron microscopy,infrared,and thermogravimetric characterization. The effects of pore structure,nitrogen content,nitrogen species (pyridine nitrogen,pyrrolic nitrogen and graphitic nitrogen) and basic sites on the reforming performance were investigated. The study found that nitrogen doping can significantly increase the nitrogen and basic site content of biomass carbon materials,providing more active sites for the reforming reaction. The nitrogen content of the biomass char material (BC-750/3.5-N) prepared by post-processing nitrogen was as high as 26.35%. The in-situ nitrogen doping can promote the activated pore formation of KOH,so that the sample NBC-750/3.5 can obtain a large number of micropores or narrow micropores. The specific surface area and pore volume are 1 981.53 m2/g and 1.08 mL/g,respectively,which are conducive to the adsorption of raw gas. Meanwhile,the characterization results show that the proportion of pyridinic nitrogen and pyrrolic nitrogen in the NBC-750/3.5 catalyst samples prepared by in-situ nitrogen doping is relatively high,which are 31% and 50%,respectively. The pyrrolic nitrogen is favorable for CO2 adsorption,and the pyridine nitrogen is favorable for molecular activation,so the prepared carbon material catalyst exhibits excellent catalytic performance. After 10 hours of catalytic reforming,the conversions of CH4 and CO2 remain stable at about 45% and 62%. It is also found that after the reforming reaction,the proportion of pyridine nitrogen and pyrrolic nitrogen decrease,and the proportion of graphitic nitrogen increases. By changing the preparation method of biochar and nitrogen doped method,the existence form of nitrogen containing groups can be more accurately regulated,so that high activity and stability of carbon-based non-regenerated catalytic materials can be obtained through controlled preparation.