A　new　type　of　optical　electrical　sensor　based　on　the　linear　measurement　of　electro-optic　phase　retardation　by　using　the　crystal　wedge　is　proposed.　Which　consists　in　having　electro-optic　phase　retardation　of　crystal　converted　into　the　shift　of　light　spot　stripe,and　phase　retardation　is　acquired　by　measuring　the　shift　of　stripe.　The　linear　relation　between　stripe　shift　and　phase　retardation　is　analyzed　and　derived,　and　the　calculation　method　for　shift　of　light　spot　stripe　is　provided.　It　is　shown　by　experiment　that　the　range　of　phase　retardation　measured,　as　an　indication　of　linearity　quality,　has　reached　320°.　©,　2015　Automation　of　Electric　Power　Press.