Abstract: The explosion limit is a crucial parameter utilized for assessing the explosion risk of combustible gases and ensuring safety measures for prevention and control of explosions. In this study, the explosive upper limits of CH4/C2H6 and C2H6/H2O mixtures were measured using a 5 L experimental platform designed to characterize combustible gas explosions. Furthermore, the impact of methane mixing ratio and water vapor concentration on the upper explosion limits of the mixture of ethane under high temperature and pressure conditions was elucidated. The results indicate that at 200 ℃ and 0.4-0.6 MPa, the effect of methane mixing ratio (0-50%) on the upper explosion limit of CH4/C2H6 mixture is minimal. As initial pressure increases, there is an increase in the upper explosion limit of CH4/C2H6 mixture; however, this increasing range exhibits a decreasing trend. At 200 ℃ and 0.4-0.6 MPa, it was observed that with an increase in water vapor concentration (0-40%), there is a linear decrease in the upper explosion limit of C2H6/H2O mixture. Additionally, as initial pressure rises, so does the upper explosion limit for C2H6/H2O mixture. At 0.5 MPa when temperature increased from 200 ℃ to 270 ℃ , both pure ethane as well as C2H6/H20 mixture containing 40% water vapor volume exhibited an increase in their respective upper explosion limits; moreover, it was observed that pure ethane displayed an upward trend regarding its rate of increase.