To enhance the tribological performance of the phosphate-bonded coating, carbon fibers (CFs) were oriented in the coating and investigated the influence of fiber orientations on the coating tribological performance. Firstly, CFs were surface-modified via a self-assembly method using polyethyleneimine (PEI), which successfully introduced positive charges onto the CFs surface. The structural and chemical characteristics of the modified CFs were systematically characterized by SEM, FTIR, Raman spectroscopy, XRD, and XPS. Subsequently, the modified CFs were incorporated into the coating, and directional alignment of CFs was achieved under an electric field. The tribological properties of coatings with different fiber orientations were then systematically evaluated. Results revealed that as the fiber orientation angle (FOA) increased, both the friction coefficient and wear rate of the coatings decreased significantly. In particular, when the CFs were oriented perpendicular to the sliding direction (90°), the coating exhibited optimal tribological performance, with a friction coefficient of 0.19 and a wear rate of 1.73 × 10−4 mm³/(N·m), representing reductions of approximately 43% and 45%, respectively, compared to the fiber orientation parallel to the sliding direction (0°). At 0°, the applied stress (σx) parallel to the fiber axis promotes fiber fracture and accelerates crack propagation. At 90°, σx acts perpendicular to the fibers, and together with σy, is redistributed and absorbed, suppressing crack penetration and enhancing the coating’s cohesive strength and wear resistance.