A　deep　understanding　of　the　fine　structure　at　the　atomic　scale　of　halide　perovskite　materials　has　been　limited　by　their　sensitivity　to　the　electron　beam　that　is　widely　used　for　structural　characterization.　The　sensitivity　of　a　gamma-CsPbIBr2　perovskite　thin　film　under　electron　beam　irradiation　is　revealed　by　scanning　transmission　electron　microscopy　(STEM)　through　a　universal　large-range　electron　dose　measurement,　which　is　based　on　discrete　single-electron　events　in　the　STEM　mode.　Our　research　indicates　that　the　gamma-CsPbIBr2　thin　film　undergoes　structural　changes　with　increasing　electron　overall　dose　(e(-).A(-2))　rather　than　dose　rate　(e(-).A(-2).s(-1)),　which　suggests　that　overall　dose　is　the　key　operative　parameter.　The　electron　beam-induced　structural　evolution　of　gamma-CsPbIBr2　is　monitored　by　fine　control　of　the　electron　beam　dose,　together　with　the　analysis　of　high-resolution　(S)TEM,　diffraction,　and　energy-dispersive　X-ray　spectroscopy.　Our　results　show　that　the　gamma-CsPbIBr2　phase　first　forms　an　intermediate　phase　[e.g.,　CsPb(1-x)(IBr)((3-y))]　with　a　superstructure　of　ordered　vacancies　in　the　pristine　unit　cell,　while　a　fraction　of　Pb2+　is　reduced　to　Pb-0.　As　the　electron　dose　increases,　Pb　nanoparticles　precipitate,　while　the　remaining　framework　forms　the　Cs2IBr　phase,　accompanied　by　some　amorphization.　This　work　provides　guidelines　to　minimize　electron　beam　irradiation　artifacts　for　atomic-resolution　imaging　on　CsPbIBr2　thin　films.