In this work, regenerated cellulose (RC)–Cu nanocomposite films with interesting single-side conductive properties were prepared using in situ coating. The structure and morphology of the films were investigated with XRD, ATR-FTIR, XPS, TG, SEM, TEM and AFM analysis. The mechanical properties and conductive performance of the films were also examined. The copper of a cellulose–cuprammonium solution was employed as the coating source as opposed to the addition of other conductive substances. The single-side coating of Cu nanocomposite film was achieved by one-step reduction based on the asymmetric surface structure of RC film. A layer of Cu nanoparticles with the thickness of ∼1 μm was coated on the coagulant-contacting surface. The RC–Cu nanocomposite films displayed high single-sided conductivity (105.6 ± 63.9 S cm⁻¹). It was found that the resistance could be tuned by changing the bending curvature. This study provides potential applications in areas such as electronic substrates, wearable electronics and sensors.