To eliminate the vibration sensitivity,a light path improved method isproposed,which makes dis charge of Sagnac effect with Sagnac effect itself and do not disturb Farady effect at all.Then the polarization states of the lights spreading in the improved light path are analyzed with Jones matrix.The experiment results are in good agreement with the theoretical analysis results,which shows that the output of the improved sensor has nothing to do with vibration.After the coupling of the half-waveplate in sensing fiber,the vibration sensitivity of Sagnac fiber-optic current sensor has been eliminated.A feasible method for the practical use of Sagnac fiber-optic current sensor is provided.