Abstract: Solving the problem of carbon nanotube aggregation and improving the interface between carbon nanotubes and matrix materials are the key to improving the properties of carbon nanotube copper-based composite films. In this study, the influence of copper-plated carbon nanotubes on the microstructure and properties of composite films has been conducted by comparing the differences in microstructure and properties between carbon nanotube copper-based composite films and copper-plated carbon nanotube copper-based composite films. This analysis involve the application of the quantum tunneling effect, DLVO theory and relevant material mechanics theories. The results indicate that at a content of 1.0% (mass fraction) of uncoated carbon nanotubes and copper-plated carbon nanotubes, the electrical resistivity of carbon nanotube copper-based composite films and copper-plated carbon nanotube copper-based composite films are 25.17 μΩ·cm and 17.73 μΩ·cm respectively. The rate of change in resistance under different bending cycles has been found to be greater for the former than for the latter. After copper plating on carbon nanotubes, the changes in their size and surface structure suppress agglomeration, enhance their joining strength with the copper matrix, and ultimately enhance the properties of composite films. Considering the influence of reinforcing materials on the microstructure and properties of composite materials, the mechanism of the influence of copper-plated carbon nanotubes on the microstructure and properties of copper -based composite films has been obtained. These findings provide a theoretical basis for subsequent research on flexible printing electronic technology.