Chemical bath deposited tin oxide film (CBD SnO2) has been demonstrated as an amazing electron transporting layer for high photoconversion efficiency (PCE) hybrid perovskite solar cells (PSCs) over 25 %. The current CBD process is normally studied for small area devices. A rapid batch production of large-area CBD SnO2 film with high and uniform performance is essential for potential upscaling of perovskite solar module. Herein, we carried out a modified batch CBD process, a double chemical bath deposition (DC), for batch fabrication of large-area (400 cm2) SnO2 films and realized a homogenized PCE with a variance (Va) of 0.127, comparing to that of control sample of Va at 2.833. We further introduced mercaptosuccinic acid (MSA) at the interface of SnO2/perovskite for convenient energy band alignment and defects passivation, which significantly improved the PCE, stability and homogeneity of the devices. As a result, the mix-cation planar PSCs reaches 21.24% with further reduced Va of 0.073. A high efficiency of 22.54% was obtained for the narrow band gap FA-based perovskite device. These results suggest high potential of this modified CBD route for large area and high efficiency perovskite module preparation.