Abstract Photocatalysis is considered an effective approach for converting CO 2 into high‐value‐added chemicals. However, practical implementation of this technology is limited by the efficiency and stability of photocatalysis. Herein, an interfacial control strategy is proposed to optimize the homogeneous‐heterogeneous hybrid photocatalysis by enhancing the interaction between light‐harvesting semiconductors (LHS) and molecular active centers (MAC). Based on this strategy, self‐assembled organic semiconductors with controlled surface architectures are constructed using 1,6‐bis(phenylethynyl)pyrene building blocks to act as LHS. Combining with the classical MAC, an excellent CO 2 photoreduction performance is achieved with a CO turnover number of > 2980 maintaining long‐term stability with a selectivity of > 90%, and an apparent quantum yield of > 2.3%. Theoretical calculations combined with in situ and transient spectroscopy studies reveal that the optimized biphase interface dominates the synergy between the homogeneous and heterogeneous photocatalysts. This strategy and the proposed mechanism of interactions will contribute to the design of future artificial photosynthesis systems.