Abstract: Axial fuel staged combustion technology has the potential advantages of clean, efficient, and stable combustion in a wide load range, but axial fuel staged combustion technology is prone to problems such as reaction zone near the nozzle and close to the wall under the condition of high hydrogen content fuel. Therefore, this paper puts forward the improvement measures of adding air film on the outer ring of axial grading nozzle, and carries out experimental research. The effect of the methane doping ratio (0~100%) on the distribution of the reaction zone is investigated, and the effect of the axial fuel staged combustion nozzle with or without air film on the lift-off height of the reaction zone under typical operating conditions is compared. The results show that with the increase of hydrogen content, the adherent effect of the reaction zone is more obvious, and the lift-off height of the reaction zone on the windward and leeward sides is different. The dynamic characteristics of the reaction zone are given by the proper orthogonal decomposition (POD) analysis. It is verified that the lift-off height of the reaction zone can be effectively improved by increasing the nozzle air film. The results of this paper contribute to understanding the distribution of axial fuel staged combustion reaction zone under different hydrogen contents, and further provide guidance for the design of axial fuel staged combustion nozzles for real gas turbines.