The computational fluid dynamics(CFD) method with moving overset grid scheme is used to simulate the aerodynamic interactions between rotors of multiple helicopters during take-off and landing. The influences of different distances between rotors and wind velocities on lift coefficients and torque coefficients are analyzed. Numerical results show that compared with the upwind rotor, the aerodynamic interactions have more influence on the downwind rotor. The aerodynamic interactions lead to the decrease of the lift coefficient and the increase of the torque coefficient for the downwind rotor. The effect of these interactions decreases with the increase of rotor distance and increases with the increase of wind velocity.