This application provides a dual-polarized radiating element, an antenna, a base station, and a communications system. The dual-polarized radiating element includes: an insulated support structure with a solid structure, where the insulated support structure includes a top part, a base, and an intermediate supporting piece that connects the top part and the base; and at least two radiating arm groups conformal to the insulated support structure, and feeding mechanisms corresponding to the radiating arm groups; the feeding mechanism includes a balun and a feeding plate, one end of the balun is electrically connected to a corresponding radiating arm group, and another end of the balun is electrically connected to a ground layer; and the feeding plate is connected to an electric lead on the base of the insulated support structure.