Abstract: Based on TRI sonic Platform version 3.0(TRIP3.0), a CFD software trip developed by China Aerodynamic Research and Develop Center, a module of three-dimensional unsteady Euler equations for a rotating machinery is developed and applied to simulate the unsteady slipstream with a propeller. In this module, dynamic structured cross grid and dual-time method are used. Furthermore, massive parallel computation and multi-grid technology are adopted to decrease the computation cost. The effectiveness of this unsteady Euler solver is validated by the calculation of the thrust and the torque of a single propeller. The comparison with experimental data is presented. Finally, the aerodynamic characteristics of a turboprop aircraft are calculated with the focuse on especially the influence of unsteady aerodynamic effect. The results show that the lift coefficient increases significantly by the unsteady slipstream. The influence of angles of attack and rotational speeds are discussed, and the vortex of propeller in the flow field is also analyzed. This work indicates that our developed three-dimensional unsteady Euler module simulates the flow field of rotating machinery rapidly, practically and efficiently. The results based on this method are close to the experimental data.