An ultra-wideband antenna with four band-notched and reconfigurable characteristics is designed in this paper. The four notch characteristics of the antenna are realized by etching a U-shaped slot slit on the antenna radiation patch and the microstrip feed line, and adding an annular opening parasitic element on the modified floor. The trapping reconfigurable characteristic is realized by adding a PIN diode switch in the band-notch structure, and the three band-notch and four band-notch characteristics are respectively realized by the opening and closing of the switch, thereby the utilization ratio of the ultra-wideband frequency band are further improved. The principle of antenna band-notch generation is analyzed, and the influence of antenna size parameters on the notch is studied. The comparison between the simulation and measurement results shows that the antenna can effectively suppress the interference of narrow-band systems in the 3-11.74 GHz. The size of the antenna is 24 mm×16 mm×0.8 mm, and the structure is compact. It can be widely used in various UWB communication systems.