Electric arc ion deposition technique was adopted to deposit TiN coating on Al2O3-based ceramic composite. Scanning electron microscopy and secondary ion mass spectrometry were used to analyze the microstructure, phase constitution, and quality of the TiN coating and the interface. Surface roughness and micro-hardness of the TiN coating were measured to evaluate its quality. Flexural strength of ceramic materials is dependent on both their inherent resistance to fracture and the presence of defects, thus it was used to investigate the effect of electric arc ion deposition technique on the surface modification of Al2O3-based ceramic composite. Experimental results show that the higher the deposition bias voltage, the better the coating quality. The TiN coating is homogeneous, with a uniform surface, and free of defects when the deposition bias voltage is 300 V. The TiN coating strongly adheres to the Al2O3-based ceramic composite, and the observed elemental inter-face diffusion strengthens the interface bonding.