Alumina oxide thin film was fabricated on K9 glass by DC magnetic filtered arc source technology and the influence of the oxygen component and cathode target current on films’ refractive index,deposition rate,extinction coefficient and surface roughness was researched. The results of experiment show that the films’ refractive index,the deposition rate and the extinction coefficient decreases with the increase of the oxygen component,but increases with the rise of the cathode target current; The surface roughness are reduced initially,but increased after. And the main reason is that the proportion of the aluminum atomsand oxygen on the surface of substrate is changed by the change of the oxygen component and the cathode target current, related to the performance of the film.