This application provides a feed structure of an antenna, an antenna, and a communication device. The feed structure includes a first cavity with a first signal cable and a second cavity with a second signal cable. The first signal cable includes a first main part and a first elastic bending part located at one end of the first main part. The first main part extends along a first direction. An extension direction of the first elastic bending part intersects with the first direction, and the first elastic bending part can be deformed towards the extension direction of the first main part. A first hole is provided between the first cavity and the second cavity. The first cavity and the second cavity are connected through the first hole. A length of the first elastic bending part in a second direction is greater than a length of the first cavity in the second direction. One end the first elastic bending part away from the first main part is connected to the second signal cable through the first hole. In this application, the first elastic bending part of the feed structure extends into the first cavity in a compressed state, to facilitate installation, save space of the feed structure, and reduce weight.