The perovskite solar cells (PSCs) are advancing toward commercialization, with the development of large‐area modules serving as a critical prerequisite. The continuous production of perovskite solar modules (PSMs) needs more time for film deposition and involves more complex sample transfer operations compared with small‐area perovskite fabrication, thus requiring broadening the process window. Here, we proposed a custom‐tailored solvent engineering strategy to broaden the prevacuum‐quenching interval window for achieving efficient PSCs and PSMs through incorporating hexamethylphosphoramide (HMPA). Due to the strong interaction between PbI 2 and HMPA, this solvent engineering delays the perovskite nucleation and growth process, leading to the perovskite film with reduced defect density and lateral heterogeneity. Besides, the stable PbI 2 ‐HMPA combination stabilizes the intermediate solvent phases in the wet film, broadening the prevacuum‐quenching interval window from 30 to 60 s. Consequently, the resulting PSCs fabricated in ambient air achieved a champion power conversion efficiency (PCE) of 24.37%, with enhanced device stability. Furthermore, the PSMs (47.94 cm 2 ) obtained a champion PCE of 20.16% with high reproducibility, demonstrating the feasibility and flexibility of our strategy to large‐scale production of perovskite devices.