Abstract: The TiSiN/Ag nano-multilayer coatings were deposited on Ti-6Al-4V alloy by multi-arc ion plating system. The composition and structure of the coating were characterized using X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy, and the hardness was tested using nanoindentation. The friction and wear properties of the coating were tested by Rtec MFT500 tribometer in seawater. The results showed that the coating had a dense structure and a clear multi-layer interface. The TiSiN layer and the Ag layer were alternately deposited. The coating contained TiN, Ag and Si₃N₄ phases, and the amorphous Si₃N₄ encapsulates the nanocrystalline TiN. Compared with Ti-6Al-4V alloy matrix, after deposition of TiSiN/Ag nano-multilayer coating, the friction coefficient was reduced by more than 0.15 in both atmospheric and seawater environments, and the wear rate was reduced by two orders of magnitude. Corrosion-friction interaction occurred in artificial seawater. The main loss was due to the synergistic effect of corrosion and friction. The tribocorrosion resistance of the coating was much better than that of the Ti-6Al-4V alloy.