The invention relates to an antibacterial composite nanometer fiber high-efficiency air filtering material and a preparation method thereof, and belongs to the field of preparation of air filtering materials. The antibacterial composite nanometer fiber high-efficiency air filtering material sequentially comprises a non-woven fabric support layer, a filter layer and a nanometer fiber filter layer, wherein the filter layer is obtained by blending antibacterial fibers and micrometer fibers. When harmful air which contains bacteria and viruses passes through the antibacterial composite nanometer fiber high-efficiency air filtering material, the antibacterial composite nanometer fiber high-efficiency air filtering material disclosed by the invention can achieve antiviral and antibacterial effects and has high filter efficiency effect on tiny particles contained in air; the antibacterial composite nanometer fiber high-efficiency air filtering material disclosed by the invention has the advantages of antibacterial effect, and high filter efficiency and relatively lower resistance on the tiny particles contained in air, can achieve the filter efficiency on oily DOP (Dioctyl-Phthalate) particles with the grain diameters of 0.3 micrometers at 99.99% and achieve the filter efficiency on sodium chloride particles of 0.07-0.2 micrometers more than 99.99%, has the advantages of light weight, softness, and the like in practical application and can be used for preparing antibacterial protective articles, such as a mask, a protective mask and application protective clothes.