Due　to　their　tunable　wavelength,　high　color　purity,　bright　emission　and　low-cost　fabrication　process,　perovskite　nanocrystals　(PeNCs)　have　attracted　broad　interest　and　exhibited　great　prospects　in　application　areas　such　as　solar　cells,　light-emitting　diodes,　photodetectors,　and　lasers.　Although　the　fabrication　of　PeNCs　and　related　optoelectronic　devices　has　witnessed　rapid　development　over　the　past　several　years,　the　poor　stability　of　PeNCs　in　an　external　environment　still　remains　a　major　drawback　which　severely　limits　the　further　improvement　and　commercialization　of　PeNC-based　devices.　Therefore,　various　techniques　and　strategies　have　been　developed　to　enhance　the　stability　of　PeNCs.　Among　them,　the　encapsulation　strategy　has　been　demonstrated　to　be　an　effective　way　to　improve　the　stability　of　PeNCs.　In　this　review,　the　origin　of　the　instability　of　PeNCs　is　first　analyzed　to　identify　the　importance　of　encapsulation,　followed　by　a　summary　and　discussions　on　recent　advances　in　the　encapsulation　of　PeNCs.　The　potential　applications　of　encapsulated　PeNCs　in　various　optoelectronic　devices　are　also　presented　to　manifest　the　necessity　of　encapsulation.　Finally,　the　further　development　and　outlook　on　encapsulation　of　PeNCs　are　analyzed　in　order　to　suggest　future　improvements　and　commercialization　of　PeNCs　and　related　optoelectronic　devices.