The invention provides a preparation method of an iron-tin oxide nanometer material. The preparation method comprises the following steps that a soluble iron source, a soluble tin source, xonotlite nanowires and water are mixed to form a reaction solution, a hydrothermal reaction is carried out, and then iron-tin oxide nanometer particles are obtained. According to the preparation method, the iron-tin oxide nanometer particles are obtained with one-dimension materials as a template and an inductive agent through inductive synthesis, specifically, the iron source and the tine source are subjected to the hydrothermal reaction with the one-dimension xonotlite nanowires as the template and the inductive agent, so that the iron-tin oxide nanometer particles are obtained, and the obtained iron-tin oxide nanometer particles are uniform in shape and size. Moreover, as for the method, no complex equipment is required, experimental operation is easy, preparation in macroscopic quantity is easily achieved, and industrialization is facilitated.