_:_Titanium_{has excellent corrosion resistance and can be used for long-term operation in boil}_{ing high concentration}_nitric_{acid medium. It is}_{an ideal}_{material for}_re_{processing equipment}_{. In this paper, SEM, EDS, XRD}_and_{XPS characterization methods were used to}_analyze_{the white attachment of the surface of}_CP-_Ti_in_{nitric acid}_with_{fluorine ion and explain its formation mechanism. The results show that when the concentration of fluorine ions is below 50 ppm, the corrosion rate of CP-}_Ti_{appears from large to small and tends to be stable. When the concentration of fluorine ions is 50 ppm and above, the corrosion rate appears from large to small and tends to large presents the "V" pattern. The phase of the white attachment of the surface of}_CP-_Ti_{is TiO}₂_._{The formation mechanism of the attachment is divided into two steps}_:_first_ly_{, the formation of porous}_film_{on the surface of the CP-}_Ti_{; secondly,} _The_TiO₂_{is gro}_{wn on the pore of porous}_film_{as the base point}_and_then_shedding.