NOVELTY - Indium-tin oxide substrate is cleaned, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate is spin-coated and sintered, to obtain indium-tin oxide/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate layer. Suspension of copper-indium sulfide powder and perovskite precursor is coated on the resultant product and annealed, to obtain dense indium-tin oxide/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate/copper indium sulfide-calcium titanate black film layer. A layer of silver paste is brushed on the resultant product and cured, to obtain cryogenic perovskite solar cell.    USE - Preparation of cryogenic perovskite solar cell (claimed).    ADVANTAGE - Cryogenic perovskite solar cell having high conversion efficiency is prepared by simple, easy, economical and efficient method.    DETAILED DESCRIPTION - Indium-tin oxide substrate is cleaned, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate is spin-coated at a speed of 1000-3000 rpm for 10-30 seconds and sintered at 150 degrees C for 10-30 minutes, to obtain indium-tin oxide/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate layer. 5-20 mu L/cm2 Suspension of copper-indium sulfide powder and perovskite precursor is coated on the resultant product and annealed at 100 degrees C for 30 minutes, to obtain dense indium-tin oxide/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate/copper indium sulfide-calcium titanate black film layer. A layer of silver paste is brushed on the resultant product by screen printing and cured at 100 degrees C, to obtain cryogenic perovskite solar cell having indium-tin oxide/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate/copper-indium sulfide-calcium titanate/silver. The suspension of copper-indium sulfide powder and perovskite precursor is prepared by mixing copper-indium sulfide powder and perovskite in N,N-dimethylformamide solution, such that the concentration of copper-indium sulfide powder is 40 %mass with respect to the concentration of perovskite, stirring and subjecting to ultrasonic dispersion. The amount of copper-indium sulfide powder is 10-40 mg/mL.