A facile method to prepare carbon nanotube/carbon fiber hybrid fiber was explored by combining electrophoretic deposition process with sizing process. The electrophoretic deposition was conducted in acid-treated carbon nanotube/N, N-dimethylformamide suspension with an annular electrode which made the electrophoretic deposition effective. Sizing process was performed using a thermoplastic sizing agent after the electrophoretic deposition. Carbon nanotubes were deposited on the carbon–fiber surface and were tightly attached to it. The wetting performance of hybrid fiber was significantly enhanced by polymer matrix. Meanwhile, the introduction of carbon nanotubes in the carbon fiber reinforced thermoplastic composites results in a 35.6% enhancement in the interfacial shear strength. Such a fabrication process is easy, effective and can be a continuous one for industrial scale.