本文用直接模拟蒙特卡罗法，对再入体驻点区域的流场、光辐射特性进行了研究．针对头部锥体驻点区（包括激波层），建立了流场中的化学反应模型，中性粒子和等离子体的热运动、粒子间碰撞的理论模型，碰撞激发辐射和化学发光辐射的物理模型．给出了样本粒子运动方向和速率、粒子碰撞对的选择等蒙特卡罗法概率模型和计算方法． In this paper, direct simulation Monte Carlo method, the reentry stagnation point flow field, light radiation characteristics were studied. For the head cone zone (including the shock layer), the chemical reaction model in the flow field, the thermal motion of the neutral particles and the plasma, the theoretical model of collision between the particles, the collision excitation radiation and the chemiluminescence emission Physical model. The model of Monte Carlo method and its calculation method are given, such as the direction and velocity of sample particle movement, the choice of particle collision pairs and so on.