An antenna of a wearable device includes a metal bottom housing of the wearable device, a printed circuit board, a metal middle housing that encircles the printed circuit board, and a communications circuit set on the printed circuit board. A slot exists between the metal middle housing and the metal bottom housing. The metal middle housing is connected to the metal bottom housing using a second connecting wire. The metal middle housing and the printed circuit board jointly serve as a ground plate. An antenna feed line is used to connect the metal bottom housing and the communications circuit module. The metal bottom housing serves as an antenna radiation body.