本文采用ICCD瞬态光谱测试系统和20L球形气体/粉尘爆炸反应装置，在当量比为1.0的条件下，测试了瓦斯爆炸过程的瞬态发射光谱，摄谱范围250~800nm，获取了整个光谱范围内的瓦斯爆炸火焰特征光谱图，并分段分析了可辨识爆炸反应过程产生的自由基等中间产物的光谱特征；针对四个中间产物OH（306.36nm）、CH（431.42nm）、C2（516.52nm）、CH2O（443.4nm），利用单色仪和光电倍增管测试了不同浓度瓦斯爆炸过程四种中间产物特征光谱强度随时间的变化规律。 结果表明：（1）在增益为1，未去除点火和自然背景光的采集模式下，25~125ms和135~235ms两种采集时间段内瓦斯爆炸光谱强度均随波长的增大而逐渐加大，表现为紫外光区光谱强度较弱，向红光方向逐渐增强；瓦斯爆炸过程中后阶段（135~235ms）光谱强度明显比前阶段（25~125ms）要大，并且随着波长的增加爆炸后阶段比前阶段光谱强度增大量幅度更大；（2）通过将增益加大，将点火和自然背景光减除的模式对8个特征波段重新进行测试，在所拍光谱范围内出现可辨识的10种自由基及分子（CH、OH、CH2O、C2、HCO、CN、NO、NH、O、O2），其中OH、CH、CH2O和C2可作为关键中间产物；（3）爆炸过程中四种中间产物的浓度与瓦斯浓度和爆炸压力之间的关系：①OH自由基浓度随时间变化最明显；②爆炸反应开始后OH自由基浓度迅速增大到达峰值，CH和C2自由基及CH2O分子随后到达峰值，随着爆炸过程的发展，CH和C2自由基及CH2O分子浓度先快速减小直至消失， OH自由基直到1000ms附近才消失；③当瓦斯浓度小于10%时，OH自由基的浓度极值随瓦斯浓度的增加而增加；当瓦斯浓度大于10%时，OH自由基的浓度极值先保持不变，直到瓦斯浓度增加到12%才开始缓慢的减小。CH和C2自由基及CH2O分子变化较一致。OH自由基浓度极值随瓦斯浓度的变化与最大爆炸压力随瓦斯浓度的变化大致相同。④在不同浓度的瓦斯爆炸过程中，OH自由基的存在时长均大于CH、C2和CH2O。

In this paper, the ICCD instantaneous spectrum detection apparatus and 20L gas / dust explosive devices are applied to study the transient emission spectra of gas explosion in the gas concentration of 9.5%. Shooting range of the spectrum is 250-800nm. Get a gas explosion flame spectra characteristic of the entire spectral range. And segmentation analysis of the spectral characteristics of recognizable free radicals during the gas explosion. An monochromator and PMT are applied to measure the characteristic spectral intensity variation with time of four key free radicals. The four key radicals are OH（306.36nm）、CH（431.42nm）、C2（516.52nm）、CH2O（443.4nm）. The result shows that :(1) In the case of containing ignition spectrum and natural background spectrum, the spectral intensity of gas explosion increases as wavelength increases in this two measure. The spectral intensity of ultraviolet region is weaker than red region’s. In 135-235ms, the increased amount of spectral intensity is bigger than 25-125ms.(2) Measuring eight special band spectrum without ignition spectrum and natural background spectrum. Several identifiable free radicals are found, such as H、OH、CH2O、C2、HCO、CN、NO、NH、O、O2. And OH、CH、CH2O、C2 can be used as the key free radials.(3) ①The most obvious is OH Free Radical concentration Versus time. ② After the explosion reaction started OH concentration increases rapidly to reach a peak. With the development of the explosion process,CH,CH2O,C2 concentration decreases rapidly at first until it disappears. Until near 1000ms the OH is disappear. ③ When the gas concentration is less than 10%, the maximum concentration of OH increases with increasing gas concentration. When the gas concentration is greater than 10% , the maximum concentration of OH to remain unchanged until the methane concentration increased 12% began to slowly decrease. The change of CH,C2 and CH2O are same. The maximum spectral intensity of OH varies with gas concentration and the maximum explosion pressure varies with gas concentration is approximately the same.④ At different concentrations in gas explosion, OH existence longer than CH,C2 and CH2O.