The invention discloses a piezoelectric pump. A central counter cavity is formed in the upper surface of a pump body, and an inflow counter cavity and an outflow counter cavity are formed in the lower surface. An inflow valve disc installation counter groove is formed in the position, opposite to the inflow counter cavity, of the bottom of the central counter cavity. The inflow counter cavity is communicated with the inflow valve disc installation counter groove through an inflow hole. The central counter cavity is communicated with the outflow counter cavity through an outflow hole. An inflow valve disc is installed in the inflow valve disc installation counter groove and seals and covers the inflow hole, and an outflow valve disc is installed at the bottom of the outflow counter cavity and seals and covers the outflow hole. A piezoelectric vibrator is installed on the upper surface of the pump body and seals and covers the central counter cavity. The inflow valve disc and the outflow valve disc are each of a dual-layer structure consisting of a thin metal layer and a thin polymer film layer, wherein the thin polymer film layers face the inflow hole/outflow hole. The piezoelectric pump is simple in structure, high in responding speed, good in valve disc switching-off performance and high in work efficiency.