A multimode broadband antenna module, comprising a printed circuit board, a first radiator, and a second radiator, wherein the first radiator comprises a connection portion, a low frequency portion, and a high frequency portion, wherein the low frequency portion of the first radiator is connected to the high frequency portion of the first radiator, and one end of the connection portion of the first radiator is connected to a joint between the low frequency portion and the high frequency portion of the first radiator, and the other end is electrically connected to a signal feeding end of the printed circuit board; the second radiator comprises a grounding portion, a low frequency portion, and a high frequency portion, wherein the low frequency portion of the second radiator is connected to the high frequency portion of the second radiator, and one end of the grounding portion of the second radiator is connected to a joint between the low frequency portion and the high frequency portion of the second radiator, and the other end is electrically connected to a first grounding end of the printed circuit board; and a first predetermined distance exists between the low frequency portion of the first radiator and the low frequency portion of the second radiator, and a second predetermined distance exists between the high frequency portion of the first radiator and the high frequency portion of the second radiator, so as to form a coupling capacitance effect between the first radiator and the second radiator; wherein the connection portion of the first radiator has a planar plate structure or a stripe structure; and the grounding portion of the second radiator has a planar plate structure or a stripe structure; wherein the low frequency portion and the high frequency portion of the first radiator are symmetrically distributed at two sides of the joint between the two, and the low frequency portion and the high frequency portion of the first radiator form a planar T-shaped plate structure together; the low frequency portion and the high frequency portion of the second radiator are symmetrically distributed at two sides of the joint between the two, and the low frequency portion and the high frequency portion of the second radiator each have a stripe structure or a plate structure, wherein the stripe structure or the plate structure extends for a distance from the joint between the two and is bent towards a direction of the first radiator; and an opening formed by a bend of the low frequency portion of the second radiator is opposite to an opening formed by a bend of the high frequency portion of the second radiator; at least one part of the low frequency portion and the high frequency portion of the second radiator is located in the same plane with the first radiator, and an angle of 90 degrees exists between the part of the low frequency portion of the second radiator that is located in the same plane with the first radiator and another part of the low frequency portion of the second radiator; wherein the part of the low frequency portion of the second radiator that is located in the same plane with the first radiator is one end of the second radiator which is bent towards the first radiator; and the part of the high frequency portion of the second radiator that is located in the same plane with the first radiator is another end of the second radiator which is bent towards the first radiator.