The hydrogen-blended combustion technology is a new technology that mixes a specific proportion of hydrogen, in the fuel, to improve combustion efficiency and reduce pollutant emissions. This technology is considered to be an effective method in improving the overall energy produced. The principle of “power to gas” technology is to take advantage of the intermittent nature of both wind-generated and solar energy, by using the surplus energy for the production of hydrogen by the electrolysis of water. The hydrogen can then be combined with carbon dioxide to produce methane, or by direct addition to natural gas in the pipeline network, thus enabling large-scale utilization of hydrogen energy. The rationality of the application of hydrogen-blended combustion technology in gas boilers is based on a simplified mechanism of GRI-MECH 3.0 of methane combustion. This reaction contains 24 elementary reactions involving 17 components. In this work, a numerical simulation experiment was designed, where atmospheric air was the oxidant, and the oxygen excess coefficient was maintained as a constant. A total of eleven groups of methane/hydrogen premixing ratios Rf (0~1) were considered and the effects of differing hydrogen blending ratios on fuel combustion temperature, combustion rate, and main pollutant emission concentrations were studied. The results showed that, by increasing the hydrogen blending ratio, both the combustion temperature and the reaction rate increased. Similarly, the concentration and the total emissions of soot and CO decreased, while the concentration of NOx increased, however, the total emissions decreased first then increased. The mechanisms relating to the effect of hydrogen mixing on the combustion process and the resultant pollutant formation were also analyzed, concerning China's urban fuel gas interchangeability regulations and industrial pollutant emission standards, the optimal hydrogen blending ratio was determined to be 23%.