The invention discloses a method for preparing a Pb3(PO4)2 nanowire film. The method comprises the following steps: depositing PbS on the surface of an electrode by using an electric deposition way to form a carrier film, immersing the electrode in a PBS buffer solution, growing for 48 to 72 hours in a constant-temperature water-bath pot, and finally taking out the electrode, wherein the Pb3(PO4)2 nanowire film spontaneously grows on the electrode. The method is simple in preparation process; and the prepared Pb3(PO4)2 nanowire film is large in adhesive force, regular in shape, large in length-diameter ratio, homogenous in diameter, high in efficiency, low in cost and easy in mass production and has potential application value in the fields such as electrode materials, sensors, plasticizers and the like.