Titanium alloy has high strength, low density, high corrosion resistance, which are being used in aerospace and chemical industries. But its low wear resistance restricts wider application. In the paper, the laser treated and untreated samples of TB5 alloys are placed in a special solid medium for oxygen diffusion. By studying the furnace heating conditions and the pretreatment process, an analysis is performed on the microstructure and hardness of TB5 alloys. What’s more, we make a comparison between TB5 and TA4 titanium alloys under the same experimental conditions. The experimental results indicated: Under the same temperature and time a hardened layer is formed on the surface of the laser treated and as-received samples. The thickness and hardness of the oxygen-diffusion zone formed on the laser treated sample are much higher than that of the as-received sample. Under the same experimental conditions, TA4 titanium samples are easier for oxygen diffusion, compared with TB5 titanium alloys.