Because　of　the　limited　information　interaction　between　protective　electrical　apparatuses　in　different　distribution　levels,　rapidity　and　global　selectivity　are　difficult　to　achieve　concurrently　in　short-circuit　fault　protection.　Based　on　short-circuit　fault　early　detection,　a　fast　and　selective　protection　technology　in　low　voltage　distribution　systems　was　presented,　in　which　the　effective　interaction　of　short-circuit　fault　information　between　fault　detection　modules　and　central　control　module　could　be　achieved　through　CAN　bus　communication.　The　overall　protection　scheme　was　illustrated,　then　short-circuit　fault　early　detection　method　and　its　key　role　in　fast　and　selective　protection　was　analyzed,　and　the　flexible　and　reliable　selective　protection　mechanism　based　on　CAN　bus　was　designed.　Finally　the　scheme　was　applied　in　simulated　short-circuit　fault　selective　protection　experiments　to　test　the　completion　time　of　selective　protection　and　observe　detailed　interaction　processes.　The　results　show　that　the　selective　protection　technology　combining　fault　early　detection　and　CAN　bus　communication　can　find　the　fault　level　fast　and　accurately,　and　give　a　breaking　command　to　the　relevant　protective　electrical　apparatus　reliably,　which　contributes　to　the　fast　and　global　selective　protection　in　low　voltage　distribution　systems.