A numerical simulation metho d for helicopter rotor/fuselage unsteady interaction flowfield is establis hed based on the hybrid grid. In this method, the hybrid grid system is used to gen erate flowfield grid to reduce the difficulty of grid generation, the combinatio n of the secondorder MUSCL scheme and Roe scheme is employed for spatial disc r etization to improve precision, and the implicit LUSGS scheme and OpenMP paral lel stra t egy are introduced to enhance efficiency. Based on the developed method, simu lat ions for Georgia and Robin rotor/fuselage model are conducted, and the g ood agreement between 〖JP2〗simulation results and experimental data demonstrat es the effectiveness of the presented method.