The propeller slipstream passed through the rotor plane when the autogyro was flying forward, in order to study the unsteady aerodynamic interference of propeller slipstream on the autorotating rotor, based on the RANS equations (Reynolds averaged Navier-Stokes), a computational analysis method for the aerodynamic interference flow field of autorotating rotor-propeller was established by using the moving overset grids method, and the model was simulated. The unsteady aerodynamic characteristics and flow field characteristics of the isolated and combined autorotating rotor at low speed were analyzed. The effects of different velocities and propeller positions on the aerodynamic characteristics of the spinning rotor were studied. The results showed that the propeller slipstream affected the lift-drag characteristics of the autorotating rotor at all azimuths, and caused the distortion of the rotor wake near 0° azimuth. Under the same rotor thrust, the larger the inflow velocity, the smaller the rotor tilt angle, and the smaller the influence of propeller slipstream on the autorotating rotor. Increasing the pitch between the propeller and the autorotating rotor can reduce the aerodynamic interference of the propeller slipstream on the rotor..