Wind power transmitted through fractional frequency wind power system (FFWPS) is a promising scheme. The voltage stability of FFWPS is a very noteworthy issue. This paper proposes a voltage control method for wind power converters based on droop control to improve the small signal stability of FFWPS. By establishing the state space small-signal modeling of the system and using the eigenvalue analysis method, it is verified that the proposed control method can effectively improve the voltage stability of FFWPS. The simulation test verifies the correctness and effectiveness of the proposed method.