Abstract: The leakage and dispersion of hydrogen-blended natural gas from buried pipelines are influenced by a complex interplay of soil media, pipeline and leakage parameters, and hydrogen blending ratios. While existing studies primarily examine individual factors, research into their coupling effects remains limited. In this study, a numerical simulation method was adopted to systematically analyze the individual effects of soil type, soil moisture, pipeline pressure, leakage aperture, and hydrogen blending ratio on gas dispersion. Orthogonal simulation tests and Pearson correlation coefficients were employed to determine the relative significance of these factors across various spatial monitoring points. The single-factor analysis indicated that the gas mole fraction increased most rapidly and reached the highest final concentration in loam, followed by sandy soil and clay. Soil moisture within the range of 0.74% to 1.4% exerted no significant effect on gas dispersion. While pipeline pressure, leakage aperture, and hydrogen blending ratio were all positively correlated with the mole fraction at monitoring points, these influences diminished as the gas dispersion distance increased. The multi-factor coupling analysis revealed that the area directly above and lateral to the leakage source was most significantly affected by the leakage aperture. Conversely, the area directly below the source was dominated by the hydrogen blending ratio, demonstrating pronounced spatial heterogeneity. This study identifies the critical controlling factors and spatial dispersion patterns of leakage from buried hydrogen-blended natural gas pipelines. These findings provide a theoretical foundation for risk assessment, the optimization of monitoring point layouts, and the development of safety protection measures.