A multi-band antenna, comprising - a feeder; and - a radiating element connected to the feeder; - a first tuning device; - a notch structure being a grounded stub and comprising a first notch structure, wherein the first notch structure is located on a side of the radiating element and connected to the radiating element in a coupling manner; and a second notch structure, wherein the second notch structure is located on a side that is of the first notch structure and that is far from the radiating element, and an end that is of the second notch structure and that is far from the radiating element is grounded; wherein - the first notch structure is selectively connectable to the ground and to the second notch structure, respectively, by the first tuning device; - the first tuning device comprises a plurality of first parallel-connected branches and a first selection switch, and the plurality of first parallel-connected branches are same or different branches; wherein the first selection switch is configured to select one of the plurality of first parallel-connected branches to connect the first notch structure to the second notch structure; and - the first tuning device further comprises a plurality of second parallel-connected branches that are connected to the ground, and the plurality of second parallel-connected branches are same or different branches, wherein the first selection switch is configured to select one of the plurality of third parallel-connected branches to connect the first notch structure to ground. - a feeder; and - a radiating element connected to the feeder; - a first tuning device; - a notch structure being a grounded stub and comprising a first notch structure, wherein the first notch structure is located on a side of the radiating element and connected to the radiating element in a coupling manner; and a second notch structure, wherein the second notch structure is located on a side that is of the first notch structure and that is far from the radiating element, and an end that is of the second notch structure and that is far from the radiating element is grounded; wherein a first notch structure, wherein the first notch structure is located on a side of the radiating element and connected to the radiating element in a coupling manner; and a second notch structure, wherein the second notch structure is located on a side that is of the first notch structure and that is far from the radiating element, and an end that is of the second notch structure and that is far from the radiating element is grounded; wherein - the first notch structure is selectively connectable to the ground and to the second notch structure, respectively, by the first tuning device; - the first tuning device comprises a plurality of first parallel-connected branches and a first selection switch, and the plurality of first parallel-connected branches are same or different branches; wherein the first selection switch is configured to select one of the plurality of first parallel-connected branches to connect the first notch structure to the second notch structure; and - the first tuning device further comprises a plurality of second parallel-connected branches that are connected to the ground, and the plurality of second parallel-connected branches are same or different branches, wherein the first selection switch is configured to select one of the plurality of third parallel-connected branches to connect the first notch structure to ground.