A piezoelectric electroacoustic transducer is disclosed. The piezoelectric electroacoustic transducer includes a diaphragm, a piezoelectric element disposed on the diaphragm, an elastic element connected with and around the diaphragm, a frame around the elastic element and being disassembled so as to adjust an inner-frame projected area of the frame, and a buffer interposed between the elastic element and the frame, wherein the frame has an inner-frame projected area less than a planar projected area of the diaphragm, the elastic element, and the buffer, such that the frame always provides a compressive stress to the diaphragm, the piezoelectric element, the elastic element, and the buffer. The piezoelectric electroacoustic transducer may be implemented as a loudspeaker or a microphone.