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%.　©　2017　Automation　of　Electric　Power　Systems　Press.