Accurately assessing the microvibration effects on the line-of-sight (LOS) stability for the space laser communication terminal (LCT) is crucial for ensuring the long-term stability of communication links. To address this challenge, an integrated modeling approach is proposed to analyze the microvibration effects on the LOS stability for the space LCT. First, the LCT’s finite-element model, consisting of the off-axis telescope antenna and the rear optical path, is built to extract the nodes’ data of each surface on the optical element under the microvibration. Then the dual quaternion, which could avoid the solution error and insufficient generalization ability of the traditional least squares method, is used to calculate the surface’s rigid body displacement on the optical element. Furthermore, combined with the LCT’s optical sensitivity matrix obtained by the regression analysis method, the LOS jitter of the terminal is calculated to evaluate the LCT’s stability and guide the structural optimization. Finally, a test is conducted to validate the reliability of the integrated modeling approach. Simulation and experimental results show that the method proposed can further improve the accuracy of analysis and guide the structural optimization of LCT.