The utility model brings forward a Pockels effect-based optical voltage sensor that comprises a shielding insulating device for generating a stable electric field, a sensing unit arranged inside the shielding insulating device, and a Faraday collimation polarization apparatus for realizing mode exchange of cross line polarized lights. The Faraday collimation polarization apparatus is arranged outside the shielding insulating device and polarization maintaining fibers are respectively connected to the two ends; and two beams of cross line polarized lights are transmitted into the Faraday collimation polarization apparatus by the polarization maintaining fiber at one end and then are transmitted to the sensing unit by the polarization maintaining fiber at the other end. According to the pockels effect-based optical voltage sensor provided by the utility model, the Faraday collimation polarization apparatus is utilized to realize the mode exchange of the two beams of cross-polarization lights. Because the Faraday collimation polarization apparatus is arranged outside the shielding insulating device, the influence of the stable electric filed in the shielding insulating device on magnetic ring of the Faraday collimation polarization apparatus can be avoided, thereby improving the accuracy and the induction sensitivity of the mode exchange of the two beams of the cross line polarized lights and the anti-interference capability of the optical path. Moreover, the provided Pockels effect-based optical voltage sensor has the advantages of being free of partial pressures and having a simple structure and the like.