Abstract: In order to suppress the influence of microvibration on the imaging of the spliced telescope, modal tests and kinetic finite element correction were performed for the mirror assembly of the co-phase devices. Due to its complex structure and contact, the model was simplified, and then based on the results of the modal test, the improved cross mode-cross mode method (ICMCM) was used to correct the dynamics of the finite element model. The step response of the corrected model was solved and compared with the measured results to verify the validity of the model correction. The test results show that the first-order frequency error of the corrected model decreases from 5.2% to 0.2%, the step response is basically the same as the displacement peaks and peak time of the six measurement points of the simulation, and the maximum error of the displacement peak is 8.8%. The research results show that after simplification of mirror assemblies and correction of ICMCM, the accuracy of the model can be maintained while improving the computational efficiency.