A numerical simulation method based on the moving-embedded grid method is developed to analyze the aerodynamic interaction between the rotor， fuselage， and horizontal tail. The validity of this method has been established by comparing the results with ROBIN fuselage and Caradonna & Tung rotor test cases. Subsequently， this method is applied to calculate the interaction flow field between the rotor， fuselage， and horizontal tail of the Z-9 helicopter during hover and forward flight. The results are then compared with numerical simulations conducted for isolated rotor and fuselage flow fields. The law of unsteady rotor/fuselage/horizontal tail interaction at various forward flight speeds is analyzed. The results indicate that the fuselage induces strong directional interference with the rotor induced velocity， leading to the tip vortex tube distortion and an increase in the peak-to-peak value of the rotor thrust coefficient. In the presence of rotor downwash， the fuselage and horizontal tail experience a complex and unsteady pressure distribution. As the advance ratio increases， the rotor wake moves away from the horizontal tail， resulting in a significant reduction in aerodynamic interaction.