TiN film is deposited on the surface of titanium alloy by IBAD. Micro arc oxidation is used to improve the rigidity of the surface of titanium alloy in the different concentration of Na
3
PO
4
. X-ray and element analysis indicates that the surface structure of titanium alloy is a mixture one contents anatase and rutile when the concentration of Na
3
PO
4
increases to 0.03 mol/L
which is better in rigidity compared with the reported research.