The invention discloses a preparation method for a one-dimensional silicon nanowire array, wherein a metal-assisted chemical etching method from the top down is adopted, the cut and cleaned silicon wafers are put into stable hydrofluoric acid aqueous solution etching liquid of metal salts, and in a supergravity system, the one-dimensional silicon nanowire array with high quality can be controllably prepared by a one-step method of adjusting the rotating speed, temperature and time of a centrifugal machine. According to the preparation method provided by the invention, the supergravity field is introduced in a reaction process, the silicon nanowire array with different shapes and high quality can be prepared by the one-step method, and the reaction time can be shortened.