For　big　data　has　been　pervasively　applied　in　many　industries　as　crucial　information　supports　and　confronted　with　lots　of　security　risks　in　the　procedure　of　collection,　storage,　transmission　and　application,　this　paper　analyzes　the　security　threats　in　big　data＇s　life　cycle,　summarizes　the　security　critical　technologies　and　new　developments　according　to　big　data　system　platforms　and　big　data　applications,　including　user　access　control,　data　isolation,　data　integration,　privacy　protection,　security　audit,　precaution　advanced　persistent　threat　etc.,　to　meet　the　new　security　challenges　and　requests　proposed　by　the　rapid　developments　of　cloud　computing,　Internet　of　Things,　mobile　internet,　etc.　It　also　prospects　the　security　tendency　for　big　data.　©　2017,　Editorial　Department　of　Journal　of　Beijing　University　of　Technology.　All　right　reserved.