Abstract: The variable-sweep angle wing represents a classic morphing wing design. This adaptive structure optimizes aerodynamic performance across diverse flight conditions by transitioning between a high-sweep configuration for supersonic flight and a low-sweep configuration for subsonic regimes. This study employs an Arbitrary Lagrangian-Eulerian (ALE) formulation to develop a sliding mesh methodology for computing unsteady aerodynamic forces during rotating variable-sweep wing morphing. Furthermore, a coupled CFD/CSD approach establishes an aeroelastic system model to investigate sweep angle variation effects at constant transition rates. The research specifically analyzes unsteady phenomena during elastic wing morphing and their impact on aeroelastic characteristics. Key findings reveal that during constant-rate sweep adjustment, wing torsional deformation induces a progressive reduction in local angle of attack, with maximum attenuation (approximately 0.1°) occurring at the mid-span region. The morphing process initiates transient wing oscillations that gradually dampen. Post-damping analysis shows: 1）Pressure coefficients exhibit over 10% deviation from static aeroelastic values at fixed configurations； 2）Aerodynamic force coefficients demonstrate less than 2% variation；3）Persistent unsteady effects from morphing significantly alter surface pressure distributions. Notably, forward-sweep motion produces distinct pressure field modifications: the root region experiences expansion of surface negative pressure zones, while the tip region shows corresponding attenuation. These findings demonstrate the complex interplay between aerodynamic loading and structural flexibility during in-flight wing morphing.