A dielectric resonator includes: two dielectric resonant cylinders and a metal cavity, wherein the dielectric resonant cylinders are located within the metal cavity; and it also includes: a fastener and a connector, wherein bottoms of the dielectric resonant cylinders are connected via the connector to form a U-shaped structure, and the connector is fixed on the metal cavity via the fastener. With the dielectric resonator of the embodiments of the present invention, a good close contact between the dielectric resonant cylinders and the metal cavity can be guaranteed, thereby improving the resonant performance of the dielectric resonator.