Antisolvent-assisted crystallization has been extensively used for perovskite solar cells (PSCs), although this approach has a fatal drawback, low reproducibility, originating from the extremely harsh operating conditions of the current antisolvents. As a result, only skilled technicians are qualified to be scheduled to prepare perovskite thin films to fabricate high-efficiency devices, which lowers the pace of progress of PSCs. Besides, the most popular antisolvents toluene (TL) and chlorobenzene (CB) are highly toxic and carcinogenic. On account of these, we tried to develop a low hazardous antisolvent that enabled us to achieve highly efficient and highly reproducible PSCs. Herein, tetraethyl orthosilicate (TEOS) was employed in the inverted NiO X-based planar PSC for engineering an efficient perovskite layer, achieving a power conversion efficiency of 17.02% on glass substrates and 14.49% on flexible polymer substrates with negligible hysteresis, which even outperformed TL and CB. More importantly, TEOS PSCs exhibited much higher reproducibility than that of their counterparts. These desirable features should be ascribed to the higher-quality perovskite films with larger grain size, reduced density of defects, and thus smoother carrier transportation and slower carrier recombination. This work drives another step toward industrial-scale commercialization of PSCs and also paves the way for environmentally friendly photovoltaic applications.