NOVELTY - A perovskite solar energy battery preparing method involves cleaning indium-tin-oxide electric conductive glass and drying with nitrogen to obtain cleaned indium-tin-oxide substrate, preparing calcium precursor solution by adding doped cadmium sulfide, dimethylformamide, methylammonium iodide and lead iodide powder, cadmium chloride powder and thiourea powder, and stirring uniformly to obtain uniform cadmium sulfide and doped perovskite precursor solution, followed by dropping poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate on the cleaned substrate, and spin coating.    USE - Method for preparing perovskite solar energy battery.    ADVANTAGE - The method enables preparing the perovskite solar energy battery with reduced energy consumption, high electron transport property, increased current density and enhanced efficiency.    DETAILED DESCRIPTION - A perovskite solar energy battery preparing method involves cleaning indium-tin-oxide electric conductive glass and drying with nitrogen to obtain cleaned indium-tin-oxide substrate, preparing calcium precursor solution by adding doped cadmium sulfide, dimethylformamide, methylammonium iodide and lead iodide powder, cadmium chloride powder and thiourea powder, and stirring uniformly to obtain uniform cadmium sulfide and doped perovskite precursor solution, where the solid liquid ratio of methylammonium iodide powder and dimethylformamide is 0.151-0.171 g/ml, the solid liquid ratio of the lead iodide powder and dimethylformamide is 0.46-0.48 g/ml, the solid liquid ratio of cadmium chloride powder and dimethylformamide is 17.33-19.33 mg/ml, the solid liquid ratio of thiourea powder and dimethylformamide is 21.85-23.85 mg/ml, followed by dropping poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate on the cleaned substrate, and spin coating. The resultant substrate is placed on a hot plate and annealed to obtain a layer of the poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate film on the substrate. The resultant substrate is placed in the precursor solution and spin coated, and dried under nitrogen atmosphere to obtain indium-tin-oxide/poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate/cadmium sulfide/methylammonium lead iodide substrate, followed by dropping phenyl-C61-butyric acid methyl ester on the resultant substrate, spin coating and baking to obtain indium-tin-oxide/poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate/cadmium sulfide/methylammonium lead iodide/phenyl-C61-butyric acid methyl ester substrate. The substrate is subjected to vapor deposition of a layer of silver electrodes in vacuum atmosphere to complete production of battery that is indium-tin-oxide/poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate/cadmium sulfide/methylammonium lead iodide/phenyl-C61-butyric acid methyl ester/silver substrate. An INDEPENDENT CLAIM is also included for a perovskite solar energy battery prepared by the method.