An oxide layer was formed on the surface of Ti after micro-arc oxidation (MAO) treatment, which contained F-, Cl- and I-. Then the bacterial adhesion test was carried out. The results show that the titanium after surface modification by MAO has certain antibacterial activity to the common flora around the implant, whether they are aerobic or facultative anaerobic bacteria. At the same time, the F-, Cl- and I- ions in the oxide layer improve antibacterial properties further. Different crystalline structures result in different antibacterial properties. Under low voltage, the antibacterial properties of Ti are better due to the main product of anatase TiO2.