The invention discloses a longitudinal gradient short-
fiber piezoelectric composite material and a preparation method thereof, and relates to the technical field of material preparation. The longitudinal gradient short-
fiber piezoelectric composite material comprises an interdigital
electrode and a piezoelectric
fiber composite layer, wherein the piezoelectric fiber composite layer is arranged between an upper
electrode and a lower
electrode of the interdigital electrode and comprises a plurality short-fiber
piezoelectric composite units, the plurality of short-fiber piezoelectric composite units are sequentially pasted along an axial direction, the axial lengths of the plurality of short-fiber piezoelectric composite units are changed in a gradient way, and each short-fiber piezoelectriccomposite unit comprises a plurality of polarization short piezoelectric fibers and a plurality of
polymer fibers. Polarization is completed before
package of the longitudinal gradient short-fiber piezoelectric
composite material, the polarization is complete and uniform, the problem of polarization dead zone is prevented, and meanwhile, the adaptability of a non-planar structure is improved. According to the preparation method of the longitudinal gradient short-fiber piezoelectric
composite material, the longitudinal gradient short-fiber piezoelectric
composite material is prepared, the structural size of the composite material is accurately controlled, and series and
mass production of the piezoelectric composite material in structure and performance are easily achieved.