We　report　a　simple,　effective,　and　universal　lattice　reconstruction　approach　to　improve　the　quality　of　perovskite　films　by　using　nonpolar　solvents　with　high　Gutmann　donor　numbers　(DNs).　We　find　that　high-DN　nonpolar　solvents,　for　instance,　ethyl　acetate,　can　interact　with　perovskite　precursors.　Such　a　solvent　can　make　the　perovskite　lattice　more　ordered　and　“harder”　and　promote　the　formation　of　heterostructures　with　low-dimensional　perovskite　impurities　and　residual　solvent　molecules.　As　a　result,　the　lattice-reconstructed　perovskite　films　exhibit　reduced　defect　densities　and　suppressed　ion　migration.　The　resultant　mixed-halide　blue　perovskite　light-emitting　diodes　(PeLEDs)　show　greatly　enhanced　tolerance　to　high　driving　current　densities　and　voltages,　demonstrating　high　brightness,　outstanding　color　stability　and　low　efficiency　roll-off.　Our　work　provides　a　deep　understanding　of　the　interactions　between　nonpolar　solvents　and　perovskites　and　offers　useful　guidelines　for　further　development　of　high-power　PeLEDs.　(Figure　presented.)　©　The　Author(s)　2024.