Abstract Effective photogenerated charge transfer and utilization have been regarded as a critical factor for achieving highly efficient photosynthesis of ammonia. However, the lacks necessary driving force in many catalysts limit the directly charge transfer. In this work, Cu porphyrin‐based monoatomic layer (PML‐Cu) is modified on face‐centered cubic structured defective CdIn 2 S 4 via solvothermal reaction, with a strong coupled interfacial Cu─S bond is constructed. Owing to the formation of axial CuS 1 N 4 polarization site, the local interfacial asymmetric configuration can be created between CdIn 2 S 4 and PML‐Cu to form a strong potential difference, inducing the rapid charge transport from CdIn 2 S 4 to PML‐Cu via Cu─S bond. Meantime, the electron‐enriched CuS 1 N 4 site is beneficial to the stabilization of * NHOH intermediate state, and then lowering the * NHO→ * NHOH rate‐limiting step energy barrier. Benefiting from these features, the PML‐Cu/CdIn 2 S 4 exhibit good NH 3 generation rate of 1979.0 µmol g −1 h −1 , with apparent quantum efficiency of 8.56% at 380 nm and 7.40% at 450 nm, respectively. This work provides an accessible pathway for designing interfacial asymmetric configuration with strong coupling to boost photocatalysis.