The invention discloses a preparation method of a novel Mn:CsPbCl<3> self-driving ultraviolet photoelectric detector. The preparation method comprises the steps that firstly, FTO/TiO <2>/ZrO <2>/Carbon porous framework is prepared by a screen printing process, and then Mn:CsPbCl<3> perovskite nano-materials are arranged in a filling mode in situ to increase ultraviolet absorption. By doping Mn into CsPbCl<3> perovskite, intermediate doping energy levels can be introduced between perovskite bands; and meanwhile, because the Mn belongs to forbidden transition and has a long exciton lifetime, andthe injection of electrons into TiO <2> can be greatly improved, so that the photocurrent response sensitivity of the device is improved.