In this paper, we propose a tunable dual-pass band filter operating in the 0.5-3 THz band based on a Dirac semimetal film (DSF). The filter consists of a Dirac semimetal material (AlCuFe) with variable conductivity depending on the Fermi energy level and a Topas substrate. The filter exhibits two passbands with center frequencies of 1.521 THz and 2.169 THz, which can be tuned by adjusting the Fermi energy level of the DSF from 90 meV to 170 meV. The center frequencies of the two passbands increase by 207 GHz and 279 GHz, respectively, achieving selectivity and tunability. Furthermore, when we increase L1 from 12 um to 16 um, the center frequency of the first passband increases from 1.455 THz to 1.548 THz, while the second passband decreases from 2.307 THz to 2.118 THz, resulting in a restructured filter response. Therefore, this work has potential applications in dual-band filters.