A broadband multiple-input multiple-output (MIMO) antenna with self-decoupling characteristics includes: a dielectric substrate, a metal patch printed on an upper surface of the dielectric substrate, and a pair of horizontal back-to-back elliptical tapered slots and a vertical elliptical tapered slot etched on the metal patch. A microstrip line and another bent micro strip line are respectively used to feed the vertical elliptical tapered slot and the pair of horizontal elliptical tapered slots, and characteristic modes of the horizontal slots excited by the bent microstrip line and characteristic modes of the vertical slot excited by the micro strip line are mutually orthogonal. By adopting the technical scheme, no additional decoupling structure needs to be introduced, and lower coupling can be realized in a wider working frequency band.