In this work, based on CsSnI3, we propose a hole transport layer-free perovskite solar cell(PSC), whose electron transport material(ETM) consists of TiO2, PCBM and C60. The solar cell was optimized by varying absorber layer thickness, defect density, doping concentration, and working temperature, which resulted in a final structure performance improvement of about 11 %, where VOC = 1.26 V, JSC = 26.519 mA/cm2, FF = 90.19 %, and PCE = 30.17 %. Compared with the previous theoretical and experimental organic–inorganic PSCs, the photovoltaic conversion efficiency of our designed solar cells has been greatly improved. In addition, the quantum efficiency reaches up to 90 % and remains over 50 % in the near 900 nm wavelength range.