In　the　digitization　course　of　college　library,　the　personal　information　security　of　library　users　meets　some　new　challenges.　The　privacy　protections　mainly　lie　in　the　information　generation,　migration,　utilization,　sharing,　storage,　destruction,　recovery　and　other　links.　Various　factors,　including　the　defects　of　the　cloud　computing　system,　hacker　attacks　and　viruses,　the　inadequate　internal　management　of　cloud　service　providers,　national　or　regional　legislative　conflicts,　may　pose　threats　to　the　personal　information　security　of　library　users.　Therefore,　we　should　perfect　the　policies　and　regulations　of　personal　information　protection,　adopt　flexible　application　strategies　of　privacy　technology,　strengthen　the　privacy　security　supervision　in　the　cloud　service　industry　and　formulate　unified　technical　standards　and　industry　guide　of　privacy　protection　so　as　to　protect　the　personal　information　security　of　library　users.　©　2016　IEEE.