The invention discloses a preparation method of polyvinylidene fluoride with a one-dimensional nanowire array structure. The preparation method is specifically implemented according to the following steps of: 1. preparation of a metal electrode layer; 2. preparation of a polymer solution; 3. spin coating of a polymer layer; 4. preparation of a polymer precast structure through a metal mould; and 5. stretching the polymer precast structure in an electric field to form a nanowire array. The polyvinylidene fluoride with the one-dimensional nanowire array structure is directly prepared on a substrate so as to avoid the problem of inconvenience in transferring, and the molten polymer rheological stretching is driven by adopting the electric field in a preparation process, so that a material obtains good piezoelectric properties in a structure preparation process. The preparation method can be used for preparing energy harvesters and sensors, and solving the problems of inconvenience in transferring and poor piezoelectric properties caused by directly preparing the PVDF (Polyvinylidene Fluoride) nanowire array with the piezoelectric properties on the working substrate in the prior art.