The　peak　prediction　of　short　circuit　current　is　very　important　for　the　realization　of　selective　protection　of　low　voltage　system,　and　it　is　still　lack　of　in-depth　study.　By　using　the　early　detection　technology　of　short　circuit　fault,　a　simulation　model　of　single　phase　short　circuit　fault　for　low　voltage　system　is　established.　The　phase　angle　of　short-circuit　fault　current　is　obtained,　and　the　characteristics　of　short　circuit　current　peak　under　different　phase　angles　are　analyzed.　Through　the　historical　data　of　short　circuit　fault　current,　the　prediction　rule　based　on　conditional　cloud　generator　is　constructed,　and　the　peak　prediction　model　of　short　circuit　current　based　on　two-dimensional　cloud　is　established.　The　experimental　results　show　that　the　prediction　method　of　short　circuit　current　two-dimensional　cloud　model　can　accurately　predict　the　fault　current,　which　can　lay　the　foundation　for　the　realization　of　low　voltage　selective　protection　technology.　©2018,　Power　System　Protection　and　Control　Press.　All　right　reserved.