The invention provides a preparation method of an Al-mixed ZnO semiconductor nanometer column, which comprises the following steps: weighing Zn powder and Fe powder, evenly mixing, and putting into a corundum boat; leading the surface of silicon wafer, which is plated with a gold film, to be downwards faced; fixing above the corundum boat; aerating with Ar gas; heating up and cooling with a furnace to prepare a ZnO nanometer seed crystal; preparing growth solution; heating up and stirring; putting the prepared ZnO nanometer seed crystal into the growth solution, and growing; taking out the silicon wafer and washing with deionized water; and naturally drying to obtain the Al-mixed ZnO nanometer column. The method combines the advantages of CVD and the advantage of the solution growth, does not need to react in vacuum, has lower growth temperature, obviously reduces the production cost, and prevents from using a reaction kettle, can be operated under normal pressure, thus simplifying experiment conditions, and is more moderate, and has simple technology and low cost.