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为了研究奥克托今（HMX）晶体的激光辐照效应，采用多种技术手段表征了HMX晶体在360 nm紫外激光下的微观结构演化。光学显微镜下观察了激光辐照下HMX晶体内部的缺陷积累直至细化开裂的过程。通过对原位拉曼光谱分析发现HMX吸收紫外光子后会激发HMX分子，引起环的振动。采用原位广角X射线散射（WAXS）、单晶衍射（SCXRD）和原位小角X射线散射（SAXS）技术研究了HMX在紫外激光辐照过程中的晶体变化及缺陷演化，发现HMX不会发生相变但会细化并产生新的缺陷。原位SAXS结果表明，激光辐照1170 min后HMX孔隙不断增多，并在10~20 nm和30～40 nm两个区域呈双峰分布。激光辐照过程中HMX的小尺寸孔隙不断增多并逐渐融合成更大尺寸的孔隙，缺陷不断累积，微孔隙延伸成微裂纹，再扩展成宏观裂纹。“,”In order to study the laser radiation effect on Octogen （HMX） crystal， various technical methods were used to characterize the microstructure evolution of HMX crystal under 360 nm ultraviolet laser. By optical microscope， the process from accumulation of defects to cracking under laser irradiation was observed in HMX crystals. In‑situ Raman spectroscopy demonstrated that the absorption of UV photons would stimulate HMX molecules， causing the ring vibration. In‑situ wide‑angle X‑ray scattering （WAXS）， single crystal X‑ray diffraction （SCXRD） and in‑situ small‑angle X‑ray scattering （SAXS） were also adopted to study the crystal changes and defects evolution of HMX under UV laser irradiation. It is found that phase transformation does not happen but some new defects generate in HMX. The in‑situ SAXS results show that the pores in HMX increase continuously after 1170 minutes of laser irradiation and a bimodal distribution exists in the region ranging from 10 to 20 nm and 30 to 40 nm， respectively. During the laser irradiation process， small pores in HMX keep accumulating and gradually merge into larger pores. Due to the accumulation of defects， the microcosmic pores extend into micro‑cracks， and then expand into macro‑cracks.