In this paper, the Ag-doped titania nanotube arrays was successfully fabricated by steps of preparation of titania nanotube arrays on the surface of pure titania and the Ag-doped technology of thermal drive, which has excellent bioactive and antibacterial performance. The researches show that the mechanism of thermal drive Ag-doped is the collaboration of thermal decomposition of silver nitrate in the limited space with the phase transition of titania at low temperature. After being soaked in saturated silver nitrate and annealed at 300℃, the titania nanotube arrays can realize not only the low temperature phase transition from amorphous to rutile, but also the low temperature decomposition of silver nitrate within it.