Sensor　technology　is　the　foundation　of　big　data　applications　in　power　system.　The　existing　optical　current　sensor　(OCS)　based　on　Malus　law　and　its　light　intensity　detection　mode　has　some　defects　of　small　dynamic　measurement　range,　big　temperature　drift　and　linear　birefringence.　In　this　paper,　a　new　type　of　OCS　which　can　achieve　linear　measurements　of　a　wide　range　Faraday　rotation　angle　was　presented.　It　used　crystal　wedge　to　convert　Faraday　rotation　angle　to　displacement　of　light　lines,　image　acquisition　system　captured　the　spot,　and　calculate　the　displacement.　Compared　with　light　intensity　detection　mode,　the　experimental　results　show　that　imaging　mode　enables　OCS　with　optical　power　independent,　large　dynamic　range　and　linearity　measurements.　Temperature　drift　on　the　measurement　results　is　also　reduced.　©　2015　Chin.　Soc.　for　Elec.　Eng..