从子结构方法（固定界面模态综合法）出发，导出了结构的自振频率和位移响应灵敏度的计算方法，该方法只需对降阶方程和各个子结构进行处理，即可实现灵敏度分析的降阶，从而为进一步开展大型复杂结构的动力优化设计开辟了途径．实例计算结果说明了该方法的正确性 Based on the substructure method (fixed interfacial modal synthesis method), the method of calculating the natural frequency and displacement sensitivity of the structure is deduced. This method only needs to deal with the reduced order equation and each sub-structure to realize the sensitivity analysis Reduce order, thus opened up the way for further carrying out the dynamic optimization design of large and complex structures. The calculation result of the example shows the correctness of the method