This paper establishes a three-dimensional structural and flow field model of the single-stage blade-disc of an aero-engine compressor rotor system. The moving reference frame(MRF) method was proven to be more accurate and efficient than the moving mesh(MM) method in terms of time-consuming and convergence. The interference of the unsteady wakes caused by the stator rotor was obtained from inner-compressor flow characteristics considering the effects of forward stator blade wakes. Analysis of unsteady aerodynamic loads of compressor shroud and hub, rotor blade pressure and suction surface demonstrates the following: an uneven flow field was found at the leading edge of the rotor blade, whose pressure and speed was lower than that at the mainstream zone, and aerodynamic loads were the most significant at the rotor leading edge and tip; the distribution of aerodynamic loads at rotor blade pressure and suction surface was the opposite, for unsteady aerodynamic loads of pressure surface, magnitude and fluctuation amplitude gradually decreased, but showed a gradual increasing trend at the suction surface. This research provides a theoretical basis for the dynamics design of the aero engine compressor blade-disc-rotor system.