The power conversion efficiency and long-term stability of perovskite solar cells are highly dependent on the synergistic regulation of multiscale factors during the fabrication process. This review systematically summarizes the device performance influence mechanisms by several key factors, ranging from precursor systems for the perovskite absorber and functional layers to overall device architectures. Particular emphasis is placed on the intrinsic correlations among molecular design of raw materials, film-formation dynamics, regulation of thin-film microstructure, interface and charge-transport-layer engineering, large-area module fabrication and system integration. Current studies indicate that precursor systems establish the foundation for high-quality perovskite films by regulating crystallization pathways, phase evolution and defect distributions. During film formation, antisolvent engineering, additive types and annealing conditions collectively regulate film crystallization processes, including grain size, crystallographic orientation, film coverage uniformity and residual stress, thereby affecting charge-carrier transport, trap-induced recombination and device hysteresis. Interface passivation and energy-level alignment of transport layers can effectively suppress non-radiative recombination losses and improve the selective extraction of charge carriers, leading to enhanced open-circuit voltage, short-circuit current density and fill factor. Meanwhile, n-i-p and p-i-n device architectures exhibit distinct advantages and challenges in terms of fabrication compatibility, interfacial stability and large-area scalability. During module fabrication and system integration, film uniformity, series interconnection losses, defect accumulation, environmental stability and encapsulation reliability jointly determine the industrialization potential of perovskite solar cells. This review further summarizes the major bottlenecks encountered in the transition from small-area devices to large-area modules, including interfacial recombination, ion migration, phase segregation, module interconnection losses and encapsulation reliability. Future research should focus on following directions: multiscale synergistic optimization across materials, film formation, interfaces, devices and modules; the development of in-situ and operando characterization/testing techniques; machine-learning-assisted process screening; and the establishment of unified, comparable and traceable stability evaluation protocols.