The invention discloses an Ag/alpha-AgVO3 extra-long nanowire compound material and a preparation method thereof. The preparation method comprises the following steps of dissolving a vanadium source, a surface active agent and an acidic adjusting agent in water, dropwise adding a silver-source aqueous solution to the vanadium source during stirring the vanadium source, the surface active agent and the acidic adjusting agent, performing a reaction for 4-10 hours under the temperature which is 80 DEG C or below, performing centrifugation, and performing washing and drying so as to obtain the Ag/alpha-AgVO3 extra-long nanowire material; and further performing heat treatment so as to obtain Ag/beta-AgVO3. The preparation method is simple in technology and easy to operate, the energy consumption and the making cost are effectively saved, besides, the product quality is stable, and industrialization is easy to realize.