The invention provides an ultra-wideband antenna for achieving a trap function based on planar double dipoles. The ultra-wideband antenna comprises a dielectric substrate and a metal antenna patch, wherein the metal antenna patch comprises a feed coupling unit, an energy transmission unit, a radiating unit and a guide unit; the feed coupling unit comprises a floor, a microstrip feeder and a slot line; the radiating unit comprises two pairs of dipoles; short dipoles are arranged at the upper part and long dipoles are arranged at the lower part; the energy transmission unit comprises two symmetrical coplanar strip lines; and the guide unit comprises two parallel parasitic metal strips which are located at the centers above the dipoles. The overall space structure is compact; an antenna backboard is tightly connected with the feeder; a radiation oscillator meets the phase requirements in a coplanar strip line power supply manner; the size is reduced; the design is convenient; the broadband radiation principle of the antenna is easy to understand; the replicability of a trap generation method is high; and a stop band with any frequency point can be achieved by the method in theory.