Halide　perovskites　are　strategically　important　in　the　field　of　energy　materials.　Along　with　the　rapid　development　of　the　materials　and　related　devices,　there　is　an　urgent　need　to　understand　the　structure-property　relationship　from　nanoscale　to　atomic　scale.　Much　effort　has　been　made　in　the　past　few　years　to　overcome　the　difficulty　of　imaging　limited　by　electron　dose,　and　to　further　extend　the　investigation　towards　operando　conditions.　This　review　is　dedicated　to　recent　studies　of　advanced　transmission　electron　microscopy　(TEM)　characterizations　for　halide　perovskites.　The　irradiation　damage　caused　by　the　interaction　of　electron　beams　and　perovskites　under　conventional　imaging　conditions　are　first　summarized　and　discussed.　Low-dose　TEM　is　then　discussed,　including　electron　diffraction　and　emerging　techniques　for　high-resolution　TEM　(HRTEM)　imaging.　Atomic-resolution　imaging,　defects　identification　and　chemical　mapping　on　halide　perovskites　are　reviewed.　Cryo-TEM　for　halide　perovskites　is　discussed,　since　it　can　readily　suppress　irradiation　damage　and　has　been　rapidly　developed　in　the　past　few　years.　Finally,　the　applications　of　in-situ　TEM　in　the　degradation　study　of　perovskites　under　environmental　conditions　such　as　heating,　biasing,　light　illumination　and　humidity　are　reviewed.　More　applications　of　emerging　TEM　characterizations　are　foreseen　in　the　coming　future,　unveiling　the　structural　origin　of　halide　perovskite＇s　unique　properties　and　degradation　mechanism　under　operando　conditions,　so　to　assist　the　design　of　a　more　efficient　and　robust　energy　material.