The invention discloses a light-control reconfigurable ultra-wide-band notch antenna used for cognitive radio. The light-control reconfigurable ultra-wide-band notch antenna comprises an antenna radiation unit, a coplanar waveguide feeder line, an FR4 medium dielectric substrate, a symmetric trapezoidal floor, a first light-control silicon switch, a second light-control silicon switch, a third light-control silicon switch, a fourth light-control silicon switch and a fifth light-control silicon switch, the antenna radiation unit, the coplanar waveguide feeder line, the symmetric trapezoidal floor, the first light-control silicon switch, the second light-control silicon switch, the third light-control silicon switch, the fourth light-control silicon switch and the fifth light-control silicon switch are positioned on a same side of the FR4 dielectric substrate, and the coplanar waveguide feeder line is positioned in the middle of the symmetric trapezoidal floor; the antenna radiation unit comprises a U-shaped monopole antenna which is connected with the coplanar waveguide feeder line, a bent symmetric groove is formed in a U-shaped surface-mount-device monopole and is symmetric according to the coplanar waveguide feeder line in shape. The light-control reconfigurable ultra-wide-band notch antenna has the advantages of small size, high omnidirectivity, wide frequency band, small switch electromagnetic interference and the like and is suitable for the field of cognitive radio.