Additive, solution and technology used for hard anodic oxidation of high-silicon aluminum alloy

The invention discloses an additive used for hard anodic oxidation of high-silicon aluminum alloy, with 10g-55g of polybasic organic acid and 0-200g of polylol in each litre of aqueous solution. The additive can lead the dissolution rate of the anode oxide film to be reduced, obviously improve the surface current distribution situation of high-silicon aluminum alloy products, and avoid ablation caused by the over intensive surface current distribution of the products, is beneficial to forming even and complete anode oxide film on the surface and improving the film forming speed and film hardness, avoids the occurrence of the ablation phenomenon, and can further improve the upper limit value of the oxidizing temperature and avoid low-temperature operations, thus simplifying the operation, saving the energy, reducing the cost and leading the film quality to be obviously improved.