Abstract: The dielectric cavity filter used for 4G base station usually adopts TE_01δ mode dielectric resonators. Its quality factor Q value is very high, but its size is relatively large. In order to miniaturize the dielectric cavity filter, TM₀₁₀ mode dielectric resonator is innovatively used. Although its Q value is relatively low, it can also meet the requirements of high band rejections. In this paper, the port coupling, magnetic coupling and electric coupling between two resonators are analyzed. Dielectric openings are innovatively used to create electric couplings, which are easy to machine and reduce manufacturing costs. Besides, an 8-pole quasi-elliptic function filter with two pairs of transmission zeros that can improve the close-to-band rejection slopes is designed and its passband is 2570 MHz to 2620 MHz, TD-LTE band. The debugging results show that the TM₀₁₀ mode dielectric cavity filter can not only meet the requirements of low insertion loss and high band rejections, but also reduce its size greatly.