An antenna system, comprising: a barrel directional antenna array, a radio frequency transceiver, and a baseband signal processing and control unit, wherein the barrel directional antenna array is formed by M directional antenna arrays, and horizontally covers a 360-degree sector, and M is an integer greater than or equal to 3; the radio frequency transceiver is configured to send and receive service data by using the barrel directional antenna array; and the baseband signal processing and control unit is configured to perform the following steps: obtaining a first service volume in the 360-degree sector, wherein a quantity of sectors in the 360-degree sector is a first sector quantity; determining a second sector quantity based on the first service volume; and dividing the 360-degree sector based on the second sector quantity; wherein the baseband signal processing and control unit is further configured to perform the following steps: dividing the M directional antenna arrays in the barrel directional antenna array based on the second sector quantity; obtaining a second service volume in a target sector, wherein the target sector belongs to the 360-degree sector divided based on the second sector quantity; and adjusting a quantity of directional antenna arrays in the target sector based on the second service volume. a barrel directional antenna array, a radio frequency transceiver, and a baseband signal processing and control unit, wherein the barrel directional antenna array is formed by M directional antenna arrays, and horizontally covers a 360-degree sector, and M is an integer greater than or equal to 3; the radio frequency transceiver is configured to send and receive service data by using the barrel directional antenna array; and the baseband signal processing and control unit is configured to perform the following steps: obtaining a first service volume in the 360-degree sector, wherein a quantity of sectors in the 360-degree sector is a first sector quantity; determining a second sector quantity based on the first service volume; and dividing the 360-degree sector based on the second sector quantity; wherein the baseband signal processing and control unit is further configured to perform the following steps: dividing the M directional antenna arrays in the barrel directional antenna array based on the second sector quantity; obtaining a second service volume in a target sector, wherein the target sector belongs to the 360-degree sector divided based on the second sector quantity; and adjusting a quantity of directional antenna arrays in the target sector based on the second service volume. obtaining a first service volume in the 360-degree sector, wherein a quantity of sectors in the 360-degree sector is a first sector quantity; determining a second sector quantity based on the first service volume; and dividing the 360-degree sector based on the second sector quantity; wherein the baseband signal processing and control unit is further configured to perform the following steps: dividing the M directional antenna arrays in the barrel directional antenna array based on the second sector quantity; obtaining a second service volume in a target sector, wherein the target sector belongs to the 360-degree sector divided based on the second sector quantity; and adjusting a quantity of directional antenna arrays in the target sector based on the second service volume. dividing the M directional antenna arrays in the barrel directional antenna array based on the second sector quantity; obtaining a second service volume in a target sector, wherein the target sector belongs to the 360-degree sector divided based on the second sector quantity; and adjusting a quantity of directional antenna arrays in the target sector based on the second service volume.