The invention relates to a hard-head anodized internal combustion engine piston. The substrate thereof is made of Al-Si alloy. The invention is characterized in that the external surface of the piston head has an anode oxide film with the thickness of 8-60 mu m. A anode oxide film generation technique adopts DC power supply anodization, and comprises the following steps: chemical-deoiling, washing with hot water, washing with cold water, polishing, washing with cold water, oxidizing and washing with cold water. The technological conditions of anodization are as follows: the voltage is 45-70 V, the oxidizing current density is 3-7 A/dm<2>, the temperature of oxidizing solution is -5-0 DEG C, and the oxidizing time is 30-60 minutes; and in the oxidizing solution, the concentration of sulfuric acid is 200-240 g/L, the concentration of oxalic acid is 15-20 g/L, and the concentration of aluminum sulfate is 0.2-0.5 g/L. The technological method is easy to master and can easily realize automatic control on parameters. The invention can greatly enhance wear resistance, corrosion resistance and high temperature impact resistance of the piston. After the piston is installed in the internal combustion engine, the service life is prolonged, and the content of exhaust emissions CO and HC is reduced.