基于应力分析设计法的基本原理，给出了通过有限元法得到应力分量后进行应力分类和应力评定的方法。通过有限元计算得到汽包封头的温度场、应力场，确定了其危险截面，并应用应力分析设计法对汽包封头的强度进行了校核。 Based on the basic principle of stress analysis design method, the method of stress classification and stress assessment after stress components are obtained by finite element method is given. The temperature field and stress field of the steam drum head were calculated by finite element method, and the dangerous section was confirmed. The strength of the steam drum head was checked by stress analysis design method.