利用超音速喷管实现化学氧碘激光器（COIL）内流场的加速降温，进而使增益有量级上的提升是激光器研究中的重大进展。但超音速内流场中存在着复杂的三维结构，流场结构与光束质量的关联机制是设计相关气动部件的重要判据。为此，采用了包含流场化学场、光场和热结构计算模块的全耦合仿真平台，数值解析了在不同流场条件下的出光性能，重点分析了内流场中不同方向上激波对近场输出光斑的影响及相互关系，从而确定了相关气动部件的优化设计方式。改善后的光束近场均匀性（F因子）提高了45%。

The utilization of supersonic nozzles to accelerate and cool the flow in the chemical oxygen-iodine laser is a significant progress in laser research. However, there are complex three-dimensional structures in the supersonic flow field. The relationships between flow structures and laser outputs are important criterions on the design of pneumatic components. The simulation system presented in the paper contains three blocks: the chemical flow calculation block, the optical calculation block and thermal structure calculation block. With the numerical platform, the analysis of the performance of laser under different flow conditions is carried out and the focus is the influence of the shock waves in the flow field on the near field laser output. According to the analysis, optimal methods are proposed. It makes an increase of the beam quality (F factor) of 45%.