This study using orthogonal test method, employing the film contact resistant as the evaluation criteria, optimized the parameters of the chemical oxidation:solution temperature was 25 ℃ , oxidation time was 5 minutes and pH value was 1 . 63 . And the film contact resistant and anti-corrosion character were both acceptable, using the optimized parameters to process the test piece of aluminum alloy. And discussed the influence to the film quality by some of the key parameters, such as the pretreatment means ( alkaline cleaning、 pickling ) , chemical conversion means ( solution temperature, oxidation time, pH value ) and dryness temperature.