Abstract: In order to explore the controllable synthesis of perovskite nanocubes and figure out how to obtain the luminescent properties of cesium-lead halide perovskite quantum dot materials through controlling the halogen composition,and realize spectral adjustability,a new synthesis method was accepted to synthesize perovskite nanocubes. Synthesizing perovskite quantum dot nanocubes in the oil phase which protected by inert gas argon,with Cesium oleate and Lead halide as precursor. Perovskite quantum dot materials with different luminescent wavelengths could be obtained by doping different proportions of Cl and I.Then exploring the optical characterization of perovskite quantum dot materials. Then synthesizing it into perovskite nanometer cube material LED and exploring the electrical properties. Therefore the feasibility of perovskite nanometer cube material LED covering the whole visible light band can be verified. Through electrical and optical characterizations,the new method can effectively synthesize perovskite nanocubes and spectral adjustable perovskite LED devices.