Background <p>Airflow interference between blade cascades directly affects the aerodynamic load characteristics of aeroengine blades, especially under off-design conditions.</p> Purpose <p>For solving the aeroelastic coupling problem, traditional CFD simulation methods are facing the challenge of grid scale and simulation efficiency.</p> Method <p>This study develops an efficient and accurate three-dimensional flow field simulation method based on wake reduced-order modeling (ROM) and investigates the effects of operating speed, radial flow angle, and inlet pressure distortion on aerodynamic load.</p> Results and Conclusion <p>The results indicate that the reduced-order aerodynamic model improves computational efficiency while maintaining calculation accuracy. Furthermore, the study shows that aerodynamic load is more stable when operating speed is 3500 r.min⁻¹, with multi-frequency vibration is much significant at the higher operating speeds. The magnitude of aerodynamic load decreases as the radial flow angle increases. Distorted conditions have an obvious influence on the peak of fluctuated amplitude, and it takes a significant variation of aerodynamic load under the II condition.</p> Significance <p>The research has an important engineering significance, and provides the guidance for aeroelastic design and optimization of aeroengine blade under the off-design conditions.</p>