Abstract: To address the precision control requirements of satellite attitude in complex space thermal environments, this study investigates thermal deflection in carbon fiber reinforced polymer (CFRP)-aluminum honeycomb sandwich structures attributed to anisotropic thermal expansion coefficients. A thermal-structural direct coupling model was developed in ABAQUS, integrating a steady-state mapped temperature field imposition with inertia relief and geometric center translation to achieve synchronous solutions of the temperature and stress fields. In a local coordinate system, the angular deflections of the star tracker reference plane and payload installation surfaces were calculated using the least-squares plane-fitting method. Results show that under low-temperature (ΔT = 89.31 °C) and high-temperature (ΔT = 102.26 °C) conditions, the maximum displacements reach 2.153 mm and 2.725 mm, respectively, while the angular deflection of the star tracker reference plane increases from -270.44″ to -386.90″. The maximum angular deflection of the payload installation surface exhibits a 41.1% increase as temperature rises. This study elucidates the tilt-twist coupling mechanism induced by asymmetric thermal stress and inertial constraints, while baffle thermal resistance and microcracks along the interface further exacerbate this deflection. The study offers quantitative insights for thermal control design, on-orbit compensation strategies, and deflection margin planning.