Metal　halide　perovskite　single　crystal　(SC)　has　attracted　wide　attentions　in　the　field　of　photoelectric　detection.　All-inorganic　perovskite　SCs　are　much　more　stable　than　the　hybrid　counterparts,　but　its　rapid　fabrications　usually　end　up　low　quality.　We　proposed　a　modified　solvent-evaporation　method　that　can　rapidly　obtain　smooth　and　transparent　high-quality　CsPbBr3　single　crystal　with　a　surface　roughness　of　only　5　nm　in　a　few　hours.　In　this　method,　the　lattice　phase　of　the　SC　and　the　growth　rate　is　precisely　controlled　by　the　solution　temperature,　which　is　raised　to　the　narrow　range　above　the　cubic-to-tetragonal　phase　transition　temperature.　This　precisely　controlled　solvent　temperature　allows　the　CsPbBr3　SC　growing　immediately　into　cubic　phase,　and　limits　the　volatilization　rate　of　solvent,　thus　inhibiting　the　defect　density.　The　SCs　grown　this　way　are　of　high　crystallinity,　as　the　half-height　width　of　the　(100)　and　(200)　peaks　of　XRD　rocking　curve　is　0.0154　degrees　and　0.0176　degrees,　respectively.　Characterization　of　photoelectric　properties　shows　great　potential　for　applications　in　X-ray　detection　and　photodetection.