The accuracy and stability of the optical voltage transformer(OVT)

which is based on longitudinal modulation Pockels effect

are greatly affected by the uniformity of the electric field distribution in the crystals. Through an electric field simulation analysis of the multisegmented longitudinal modulation Pockels effect OVT

it is known that the electric field distribution in the BGO crystal is not uniform. When the position of crystal and the angle of incident light have a small deviation

the integral voltage error of the optical path in crystal is in general approaching or greater than 0. 2%. To improve the electric field distribution in the crystal

a new method of quartz medium stratification is presented for the multisegmented longitudinal modulation Pockels effect OVT

and its effectiveness is verified by the finite element software ANSYS Maxwell and experiment. On the premise of ensuring the measuring sensitivity and an increase of the half wave voltage

the electric field integral error can be reduced to less than 0. 05% that meets the requirement of 0. 2%. This work is supported by National Natural Science Foundation of China(No. 51177016).