Abstract: A numerical method for simulating the unsteady flowfield and calculating the aerodynamic load of the helicopter rotor in forward flight has been developed.In this method,the 3-D unsteady Navier-Stokes equations are discretized by the combination of the third-order upwind scheme（MUSCL） and flux-difference splitting scheme,the Spalart-Allmaras one-equation turbulence model has been employed for better simulating the flow separation,and the numerical method updates the solution in time using the dual-time stepping method.To account for the rigid blade motions in rotation,flapping and pitching,a moving embedded grids methodology has been presented.Besides,in order to reflect the actual movement of the rotor blades,a rotor trim analytical model and solver are developed.With the developed method,the flowfield and aerodynamic performance of a four-bladed UH-60A rotor with advanced aerodynamic shapes in hover are calculated firstly.Based on this,simulated results about the aerodynamic characteristics（surface pressure distributions,rotor torque,aerodynamic loads） are emphatically conducted for a two-bladed Caradonna model rotor in non-lifting forward flight and the AH-1G rotor in forward flight with the occurrence of blade-vortex interaction phenomena.The numerical results agree well with experimental data,and it indicates that the present method is effective to calculate the flowfield and aerodynamic loads of the helicopter rotor in forward flight.