The work aims to analyze the dry sliding wear behavior and wear characteristics of Ti6Al4V alloy at different sliding speed and study the wear mechanisms of titanium alloy and the role of tribo-layers and tribo-oxides in dry sliding wear process. Dry sliding wear tests of Ti6Al4V alloy at different sliding speed were preformed on a pin-on-disk wear tester. The wear behavior of titanium alloy was characterized by wear rate and friction coefficient. The morphology and composition of worn surfaces and tribo-layers were analyzed by scanning electron microscopy, X-ray diffraction and energy dispersive spectroscopy, and the mechanical properties of tribo-layers were characterized by digital microhardness tester. As sliding speed varied in the range of 0.5~4 m/s, the wear rates of Ti6Al4V alloy varied obviously, especially at high loads. The wear rates were lower at 0.5 m/s to 1.5 m/s, but reached the highest at 2.68 m/s, and the lowest at 4 m/s. At 0.75 m/s, adhesion and abrasive wear were the primary mechanisms, while oxidation wear was the secondary mechanism. The wear mechanisms at 2.68 m/s and 4 m/s were delamination and oxidative mild wear, respectively. Tribo-layers with no oxides and low hardness corresponded to the maximal wear rate at 2.68 m/s, while tribo-layers with more oxides and high hardness corresponded to the minimal wear rate at 4 m/s. The wear behavior and wear mechanism of Ti6Al4V alloy vary with the test conditions. The distinct characteristics of tribo-layers are found to correspond to the wear behavior in various conditions. When tribo-layer contains some quantity of tribo-oxides, such ceramic tribo-layer has higher hardness than the matrix, thus effectively protecting the matrix and reducing the wear rate.