AbstractA dual‐layer fluorine‐doped tin oxide (FTO) film has been fabricated by means of sequential spray pyrolysis for high‐efficiency perovskite solar cells (PSCs). The H‐FTO/L‐FTO dual layer film consists of a H‐FTO layer prepared at high deposition temperature (≈450 °C) and a L‐FTO layer, fabricated at low deposition temperature (≈150 °C), which is used to replace the traditional compact TiO₂/FTO layer. The effects of F/Sn molar ratio, precursor solution concentration, and deposition temperature on the electrical, optical, surface morphological, and grain structural characteristics of H‐FTO layers have been studied systematically. With an increase in precursor solution concentration, the mobility and carrier concentration of H‐FTO increases; however, the grain size and sheet resistance decreases as the precursor solution concentration increases. A high deposition temperature results in a large grain size and enhanced haze value. The L‐FTO layer expresses compact layer growth, inconsistent with the H‐FTO surface structure, and possesses excellent electron collection and transport efficiency. The effect of the hole‐blocking characteristics of L‐FTO on the PSC performance is studied. This study provides a novel dual‐layer FTO film to replace the traditional compact TiO₂/FTO layer, which is usually prepared by coating TiO₂ precursor on FTO following calcination at 450 °C. The H‐FTO/L‐FTO dual‐layer film can simplify the fabrication process and maintain a high power conversion efficiency (PCE); this results in more efficient electron transportation and blocking of holes. The champion device of PSCs with H‐FTO/L‐FTO shows the highest PCE of 17.37 % under the illumination of 100 mW cm⁻² (AM1.5G).