The invention provides a miniaturized composite right/left-handed structure broadband filter. The miniaturized composite right/left-handed broadband filter comprises a back copper coating layer, a dielectric substrate and a front circuit, wherein the back copper coating layer, the dielectric substrate and the front circuit are arranged in sequence from bottom to top, the front circuit comprises five composite right/left-handed transmission line resonators, each composite right/left-handed transmission line resonator comprises an interdigital part, a straight microstrip line, a through hole welding disc and a metallized through hole, the five composite right/left-handed transmission line resonators are vertically arranged in parallel, the interdigital parts and the straight microstrip lines of every two adjacent resonators are alternately arranged up and down, and two microstrip lines are respectively connected to the straight microstrip lines of the resonators on the left and right ends so as to be used as input and output ports. The miniaturized composite right/left-handed structure broadband filter contains the novel composite right/left-handed transmission line resonators, and compared with a traditional resonator, the novel composite right/left-handed transmission line resonators are compact and small; the interdigital parts and the straight microstrip lines of every two adjacent resonators are alternately arranged up and down, and strong coupling is generated between resonant elements, so that a broadband bandpass filter is favorably formed, and the size is greatly reduced in the condition that broadband bandpass characteristics are realized.