A shear vibration-based piezoelectric composite material and a preparation method therefor. The piezoelectric composite material comprises piezoelectric materials (1) and a passive material (2); the piezoelectric materials comprise a piezoelectric material which is positively polarized along an X axis and a piezoelectric material which is negatively polarized along the X axis; the piezoelectric materials in two polarization directions are alternately arranged along the X axis; the passive material comprises a filling layer (2a), a transitional layer (2b), and a planar layer (2c); the filling layer is provided between every two adjacent piezoelectric materials; the planar layer is located outside two surfaces, perpendicular to a Z axis, of the piezoelectric materials, wherein the planar layer on one side is fixedly connected with the filling layer in odd-number positions by means of the transitional layer, and the planar layer on the other side is fixedly connected with the filling layer in even-number positions by means of the transitional layer. The piezoelectric composite material can be used for preparing an underwater acoustic transducer, a hydrophone and a piezoelectric energy harvester and the like; and shear vibration is creatively converted into thickness vibration on the upper and lower surfaces of the composite material, so that the performance of the composite material is improved.