Abstract: Carbon Fiber Reinforced Polymer (CFRP) composites are increasingly used in aerospace, military, and automotive lightweighting applications due to their high specific strength and stiffness, as well as excellent corrosion resistance. However, traditional CFRP suffers from two primary drawbacks: inherent brittleness and significant electrical anisotropy as poor electrical conductivity in the in-plane transverse (XY-2) and through-thickness (Z) directions. Therefore, integrating toughening and conductivity improvement is of critical importance for multifunctional applications. This study developed a synergistic strategy by designing a multi-scale hybrid interlayer, termed copper-CNTs-PA (CCP). The interlayer utilizes a nylon (PA) non-woven fabric as the structural skeleton, where copper wire of 50 µm diameter was integrated onto the fabric pre-loaded with carbon nanotubes to construct a robust three-dimensional conductive network. Experimental results demonstrated that, compared to traditional control samples without interlayers, the CCP-modified laminates exhibited significant enhancements. The Mode I (G_IC) and Mode II (G_IIC) interlaminar fracture toughness values increased remarkably by 22.78% and 49.65%, respectively. Simultaneously, the electrical conductivity in the XY-2 and Z directions reached 1028.27 S/m and 2.09 S/m, respectively. These findings confirm the successful synergistic improvement of toughness and electrical conductivity, overcoming the trade-off typically imposed by insulting toughening agents.