Abstract: All inorganic carbon-based CsPbI₂Br perovskite solar cells (C-PSCs) have lower photoelectric conversion efficiency due to poor contact performance and mismatch of energy band between carbon electrode and perovskite laye. In this paper, two kinds of regular octahedral Cu_xO with different morphologies and structures were prepared by a simple glucose reduction method combined with calcination technology. As inorganic hole transport materials, C-PSCs with the structure of conductive glass (FTO)/SnO₂/CsPbI₂Br/CuO/C were prepared and the influence of morphologies and structures on the photoelectric performance was studied. The results show that Cu_xO has good chemical stability and p-type carrier transport characteristics, which can effectively enhance the interface contact between CsPbI₂Br and carbon electrode, improve the carrier transport performance, reduce charge recombination, and extend the photoelectron life. The highest photoelectric conversion efficiency of CsPbI₂Br based C-PSCs devices based on Cu₂O and CuO is 11.62% and 13.22%, respectively, which is 19.5% and 36.0% higher than that of blank devices. In addition, by adding Cu₂O and CuO, the long-term stability of the device in the air is also significantly improved. This work has a certain significance for improving the performance of CsPbI₂Br based C-PSCs.