A transverse magnetic (TM) mode dielectric filter includes an enclosure, a dielectric resonator, a main cover, and an elastic component, where the dielectric resonator is disposed in a resonant cavity of the enclosure; the main cover is secured between the elastic component and an open end of the enclosure; the elastic component includes multiple elastic flaps; the multiple elastic flaps are evenly distributed around an axial direction of the dielectric resonator; one end of each of the elastic flaps is fixedly connected to the main cover, and free ends of the elastic flaps elastically act on a central part of an outer surface of the main cover, to provide an elastic force towards the dielectric resonator. The evenly distributed multiple elastic flaps produce a pressure towards the dielectric resonator. A uniform and stable pressure is produced around the dielectric resonator, to ensure a uniform current density inside the resonant cavity.