Based on the excitation of the CCA, the microvibration response of the SC can be calculated, achieving the dynamic decoupling analysis of the complex coupled system. Decoupling analysis indicates that in the frequency range of 8–300 Hz, the RMS values of the microvibration force and torque of the SC are 0.25 N and 0.08 N·m, respectively, meeting the requirements of the SC (≤0.4 N and ≤0.1 N·m). Future work can be extended in several directions to enhance the practical application and generalization ability of the proposed method. First, the methodology can be adapted to other types of space payloads with diverse structural characteristics (e.g., flexible attachments, multi-source excitation, or irregular interface distributions), expanding its engineering application scope to satellite antennas, precision spectrometers, and other high-precision space instruments. Second, integrating machine learning algorithms (such as neural networks or Gaussian process regression) into the finite element method (FEM) iterative correction process may improve the accuracy and efficiency of the model, especially for complex coupled systems with high-dimensional parameters.