The embodiments of the present disclosure provide an antenna element and a terminal device. The antenna element includes a target metal groove, M feeding components disposed at the bottom of the target metal groove, M feeding arms and a first insulator disposed in the target metal groove, and a target radiator carried by the first insulator. Each feeding component of the M feeding components is electrically connected to a feeding arm, the M feeding components are isolated from the target metal groove, the M feeding arms are located between the target metal groove and the first insulator, the M feeding arms are distributed along the diagonal direction of the target metal groove, each feeding arm of the M feeding arms is coupled to the target radiator and the target metal groove, a resonance frequency of the target radiator is different from a resonance frequency of the target metal groove, and M is a positive integer.