In order to minimize the aerodynamic drag of coaxial rigid rotor hub, the airfoil cross-section vortex generator installed on the shaft fairing. The vortex generator installation programs with different expansion length, chord length, installation number and locations are designed, then calculate and analysis the drag characteristics of coaxial twin hub by the method of solving N-S equation. Finally, the surface pressure and spatial flow are analyzed. The results show that vortex generator can reduce about 5% of the drag of coaxial twin hub drag reduction program. The increment of chord length and the movement of vortex generator to lower hub is conducive to further reduce the drag. The research results can provide a reference for the application of vortex generator and the drag reduction design of rotor hub.