The interface tailoring is crucial for the efficiency and stability of Perovskite Solar Cells (PSCs). The reported interface engineering primarily focuses on the energy level turning and trap state passivation to improve the photovoltaic performance of PSCs. In this review, molecule modifications are classified according to the basics of electron transfer mechanisms for the interface tailoring of materials. An in-depth analysis of energy level modification and trap passivation, as well as the universal Density Functional Theory (DFT) method employed in interface tailoring. In addition, strategies to address environmental protection and large-scale mini-modules fabrication by interface engineering are also discussed. This review can guide the researchers in understanding interface engineering to design interface materials for efficient, stable, and eco-friendly PSCs.