A high-speed color video camera was adopted to study the premixed methane-air flame propagation charac-teristics under 3 typical concentrations in a square plexiglass tube of 1 .5 meters long and a cross section of 0.1 m ×0.1 m. As the results,the flame movement can be divided into 3 stages involving flame growing stage,flame accelerating stage and flame vanishing stage.When the volume fraction of methane is slightly higher than the optimum value,the flame propaga-tion velocity can reach to the maximum value.The relationships between the flame front location and the time after ignition meet the curve of GaussAmp,and the fitting degree and its correlation coefficient are high.The flame propagation velocity-time curve via the differential of the flame front location-time curve revealed the actual instantaneous values of the flame propagation velocity.The flame movement images analysis and the calculation method of instantaneous flame propagation velocity could be references for studying the gas flame characteristics in experimental tubes or in mine roadways.%采用高速摄像研究了长1．5m、截面0．1m ×0．1m半开口有机玻璃方管内3种典型浓度下瓦斯预混火焰传播特征。结果表明：典型的瓦斯火焰运动过程分为火焰成长期、火焰加速期和火焰消失期3个阶段；甲烷体积分数略高于最佳值时，管内瓦斯火焰传播速度较大；3种典型浓度下光滑管道内瓦斯火焰传播阵面-点火时间满足GaussAmp曲线，其拟合度较高、相关性好；由火焰阵面-时间拟合曲线微分得出的火焰传播速度-时间曲线，更能反映实际瞬时火焰传播速度情况。火焰运动图像分析及瞬时火焰传播速度计算方法，对管内气体火焰或矿井瓦斯火焰特征研究具有一定的借鉴作用。
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