Rotorcraft aerial manipulator (RAM) system is an aerial robot with manipulators. When performing precise operation in hovering mode, there exists relative disturbance between the rotorcraft aerial vehicle and the manipulator, which cannot be eliminated through establishing dynamic models of the manipulator and the rotorcraft separately. In this research, the overall dynamics model is firstly developed based on dynamic disturbance of the both components, which is simplified as a linear control reference model in hovering mode. The dynamics disturbance caused by rotor system's control delay is compensated, and a predictive controller is designed to eliminate the errors of position and attitude of the end-effector. At last, control strategies are compared in simulative peg-in-hole tasks in cases of external and internal disturbances. The effectiveness of the proposed model and control method is verified by the simulation results of end-effector pose error.