The invention provides a piezoelectric micro-electromechanical system (MEMS) microphone includes a base with a cavity and a piezoelectric diaphragm arranged on the base. The base has a ring base and a support column. The piezoelectric diaphragm includes a plurality of diaphragm sheets. Each diaphragm sheet has a fixing end connected with the support column and a free end suspended above the cavity. The widths of the diaphragm sheets are gradually increased from the fixing ends to the free ends. According to the piezoelectric MEMS microphone provided by the invention, under sound pressure, the free ends vibrate, wide free ends drive short fixing ends, and the diaphragm sheets close the fixing ends generate greater deformation to generate more charge. Therefore, the sensitivity can be further improved.