给出了神光Ⅲ原型装置主放大器系统的热畸变模型 ,该模型包括三个模块 :热传输模块、热弹性力学模块、光学模块。利用该模型对原型装置的剩余热波前畸变进行了研究。初步结果表明 ,通过优化的冷却方案 ,可以在装置预定的运行周期内将激光工作介质内的温度梯度和总体平均温度冷却到可以接受的水平 ,剩余热波前畸变满足设计要求。利用该模型还定量地研究了增益介质的热膨胀系数与剩余热畸变之间的关系 The thermal distortion model of the main amplifier system of SG prototype III is given. The model includes three modules: heat transfer module, thermoelasticity module and optical module. The model was used to study the residual thermal wavefront aberration of the prototype device. The preliminary results show that the optimized cooling scheme can cool the temperature gradient and overall average temperature of the laser working medium to an acceptable level within the predetermined operating cycle of the device, and the remaining thermal wave front aberrations meet the design requirements. The model is also used to quantitatively study the relationship between the thermal expansion coefficient of the gain medium and the residual thermal distortion