The invention relates to a high-speed preparation method of an extra small bore diameter porous anodized aluminium film, belonging to the fields of a metal surface treatment technology and a nanotechnology. An extra small bore diameter PAA (Porous Anodized Aluminium) film is prepared on the surface of an aluminum sheet at high speed by a three-time new anodic oxidation process. In the first-time anodic oxidation, the voltage is 1-10V, the temperature is controlled to be 0-60 DEG C, the electrolysis time is 30 minutes to 2 hours, and a sample is washed with deionized water; a porous alumina layer formed by the first-time anodic oxidation is removed by chemical corrosion; in the step two, the electrolysis process is same as that of the step one, the electrolysis time is 5 seconds to 60 minutes, and then a protecting layer is formed; in the third time anodic oxidation, the voltage is 20-100 V, and the temperature is kept at 0-60 DEG C. The bore diameter of the extra small bore diameter PAA prepared with the method is less than 20 nm, the growth rate is 4-250 mu m/h and is 20-250 times that of the common processes. The three-time anodic oxidation process does not need complicated preindenting and polishing, has low requirements on temperature control, and has good stability, high preparation rate and shorter reaction time.