The existence of serious hysteresis effect for regular perovskite solar cells (PSCs) will affect their performances, however, the inverted PSCs can significantly suppress the hysteresis effect. To data, it has been very rarely reported to simulate the inverted planar heterojunction PSCs. In this paper, the effects of hole transport material (HTM), electron transport material (ETM), and ITO work function on performance of inverted MAPbI ₃solar cells are carefully investigated in order to design the high-performance inverted PSCs. The inverted MAPbI ₃solar cells using Cu ₂O, CuSCN, or NiO _xas HTM, and PC ₆₁BM, TiO ₂, or ZnO as ETM are simulated with the program AMPS-1D. Simulation results reveal that i) the inverted MAPbI ₃solar cells choosing NiO _xas HTM can effectively improve the photovoltaic performance, and the excellent photovoltaic performance obtained by using TiO ₂as ETM is almost the same as by using ZnO as ETM; ii) the ITO work function increasing from 4.6 eV to 5.0 eV can significantly enhance the photovoltaic performances of Cu ₂O— based and CuSCN— based inverted MAPbI ₃solar cells, and the NiO _x— based inverted MAPbI ₃solar cells have only a minor photovoltaic performance enhancement; iii) based on the reported ITO work function between 4.6 eV and 4.8 eV, the maximum power conversion efficiency (PCE) of 27.075% and 29.588% for CuSCN— based and NiO _x— based inverted MAPbI ₃solar cells are achieved when the ITO work function reaches 4.8 eV. The numerical simulation gives that the increase of hole mobility in CuSCN and NiO _xfor ITO/CuSCN/MAPbI ₃/TiO ₂/Al and ITO/NiO _x/MAPbI ₃/TiO ₂/Al can greatly improve the device performance. Experimentally, the maximum hole mobility 0.1 cm ²·V ^–1·s ^–1in CuSCN restricts the photovoltaic performance improvement of CuSCN— based inverted MAPbI ₃solar cells, which means that there is still room for the improvement of cell performance through increasing the hole mobility in CuSCN. It is found that NiO _xwith a reasonable energy-band structure and high hole mobility 120 cm ²·V ^–1·s ^–1is an ideal HTM in inverted MAPbI ₃solar cells. However, the increasing of electron mobility in TiO ₂cannot improve the device photovoltaic performance of inverted MAPbI ₃solar cells. These simulation results reveal the effects of ETM, HTM, and ITO work function on the photovoltaic performance of inverted MAPbI ₃solar cells. Our researches may help to design the high-performance inverted PSCs.