The present application relates to a flexible piezoelectric transducer and a system, the flexible piezoelectric transducer comprises: a flexible substrate which is circular in a first state and concave spherical in a second state, and which is capable of dynamically changing the radius of curvature by bending deformation; a flexible piezoelectric film layer which is arranged on the flexible substrate, at least one spiral electrode strip is arranged on the upper surface of the flexible piezoelectric film layer, the at least one spiral electrode strip has the same original point, and a fully-coated electrode is arranged on the lower surface of the flexible piezoelectric film layer. According to the flexible piezoelectric transducer and the system, the equipment integration degree is improved; by means of bending deformation of the flexible substrate and the flexible piezoelectric film layer, after phased excitation of acoustic spiral wave beams, the depth of a focal spot can be dynamically changed, the directivity of an emission array element is widened, energy superposition in a focusing area is enhanced, focusing acoustic vortex change is stable, and a long distance can be maintained in the propagation direction.