The invention relates to a perovskite solar cell light-absorbing layer nano sol film-coating solution.The perovskite solar cell light-absorbing layer nano sol film-coating solution is prepared by mixing a perovskite light-absorbing material and rare earth europium and terbium doped nano titanium dioxide sol, a perovskite solar cell nano titanium dioxide gel light-absorbing layer can be obtained through direct film coating, and the formed light-absorbing layer can firmly attach to a substrate material without high-temperature sintering, can absorb ultraviolet light and visible light in a solar spectrum and is prepared from rare earth europium and terbium doped nano TiO2 with the average particle size of 50 nm, nano TiO2 with the average particle size of 5 nm, an organic silicon coupling agent, deionized water, HCl, PbX2, CH3NH3X and an organic solvent.The perovskite solar cell nano titanium dioxide gel light-absorbing layer is obtained through one step, a film layer is uniform and good in adhesive power, a preparation process is simple, convenient and low in cost, and expansion and industrialization are easy.