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为分析CL‑20/HMX共晶和HMX冲击波感度接近的机理，采用反应分子动力学方法（ReaxFF‑MD），探讨了有无缺陷CL‑20/HMX共晶在冲击加载下的力‑热结构变化和初始化学反应，通过动量镜原理与最大压缩点吸收波阵面相结合方式，分析了快速结构响应和随后缓慢化学反应过程。结果表明，冲击加载无缺陷CL‑20、HMX和CL‑20/HMX共晶时，CL‑20的分解速度比HMX快，CL‑20/HMX共晶的分解速度与HMX接近；与沿CL‑20/HMX共晶［111］晶向加载相比，沿［100］晶向分解更快，这与CL‑20和HMX分子层的交替排布及滑移等因素有关。以2 km·s-1的质点速度沿［100］晶向冲击加载含Φ20 nm孔洞的CL‑20/HMX共晶时，孔洞周围结构没有产生射流现象，而是粘塑性收缩过程。孔洞塌缩形成的高温高压条件和结构上的粘塑性变形有效促使CL‑20和HMX分子发生快速分解，孔洞塌缩新热点的形成进一步增强了冲击加载过程。“,”In order to analyze the mechanism of shock sensitivity of CL‑20/HMX cocrystal close to that of HMX， ReaxFF molecular dynamics simulation was used to investigate the mechanical‑thermal structural changes and subsequent initial chemical reactions in CL‑20/HMX cocrystals with or without voids. The structural deformation and subsequent chemical reaction process are effectively analyzed by using the momentum mirror model combined with shock‑front absorbing boundary condition. When shocks subjected to CL‑20， HMX， and CL‑20/HMX， it is found that the decomposition speed of CL‑20 is faster than that of HMX， while CL‑20/HMX's decomposition speed is very close to HMX's. Besides， the decomposition speed of CL‑20/HMX ［100］ shocks is faster than ［111］ shocks. This phenomenon is related to alternative arrangement of CL‑20 and HMX molecular layers and the relative slip amount. When CL‑20/HMX with 20 nm diameter void is shocked along the ［100］ direction at particle velocity of 2 km·s-1， hydrodynamic jet collapse does not occur instead of viscoplastic pore collapse. It largely promotes the rapid decomposition of CL‑20 and HMX molecules in the high temperature and high pressure conditions formed by pore collapse and the viscoplastic deformation of crystal structure. A new hot spot formation from the void collapse further enhances the shock loading process.