本文采用脉冲分子束和飞行时间质谱技术研究在UV激光辐照下环氧乙烷多光子电离和解离过程,测得在308nm激光辐照下主要解离产物为HCO~+。CH~+和C_2H_3O~+.其光强指数分别为2.8,2.9和2.9.此外也观察到少量CH_2~+,CH_4~+,和H~+等产物离子.在355nm激光辐照下主要解离产物为HCO~+,CH_3~+,CH_2~+,CH~+和CH_3CO~+以及少量H~+和C~+等.对于HCO~+,CH_3~+,CH_2~+,CH~+和H~+离子,其光强指数依次为4.0,3.1,3.5,3.7和4.1.根据实验结果,对于环氧乙烷多光子电离和解离过程的机理作了讨论. In this paper, pulsed molecular beam and time-of-flight mass spectrometry were used to study the multiphoton ionization and dissociation of ethylene oxide under UV laser irradiation. The main dissociation product of HCO + was measured under 308 nm laser irradiation. CH ~ + and C_2H_3O ~ +. The light intensity index was 2.8, 2.9 and 2.9, respectively. In addition, a few CH_2 ~ +, CH_4 ~ + and H ~ + ions were also observed. The products are HCO ~ ​​+, CH_3 ~ +, CH_2 ~ +, CH ~ + and CH_3CO ~ + and a small amount of H ~ + and C ~ + etc. For HCO ~ ​​+, CH_3 ~ +, CH_2 ~ +, CH ~ + and H ~ + Ions, and their light intensity indexes are 4.0, 3.1, 3.5, 3.7 and 4.1 in order, respectively.According to the experimental results, the mechanism of multi-photon ionization and dissociation of ethylene oxide is discussed.