A method for controlling a transmit power of a wireless communications terminal, wherein the wireless communications terminal comprises a first controller (105, 1051, 1052), a WiFi controller, and a WiFi antenna, and the method comprises: determining, by the first controller (105, 1051, 1052), that the WiFi antenna is in a working state, and determining a service type of the WiFi antenna; and obtaining, by the first controller (105, 1051, 1052), a transmit power of the WiFi antenna according to a preset correspondence, and sending the transmit power of the WiFi antenna to the WiFi controller, wherein the transmit power of the WiFi antenna obtained by the first controller (105, 1051, 1052) is used to control, after the WiFi controller receives the transmit power of the WiFi antenna, the WiFi antenna to perform transmission according to the transmit power; and the determining, by the first controller (105, 1051, 1052), a service type of the WiFi antenna comprises: determining, by the first controller (105, 1051, 1052), that the wireless communications terminal performs voice communication by using the WiFi; and the wireless communications terminal further comprises an optical proximity sensor, and the method further comprises: determining, by the first controller (105, 1051, 1052), that the optical proximity sensor is triggered; and the obtaining, by the first controller (105, 1051, 1052), a transmit power of the WiFi antenna according to a preset correspondence comprises: obtaining, by the first controller (105, 1051, 1052), the transmit power of the WiFi antenna according to the preset correspondence, wherein the correspondence is used to determine, based on the case that the WiFi performs voice communication and the case that the optical proximity sensor is triggered, the transmit power of the WiFi antenna. determining, by the first controller (105, 1051, 1052), that the WiFi antenna is in a working state, and determining a service type of the WiFi antenna; and obtaining, by the first controller (105, 1051, 1052), a transmit power of the WiFi antenna according to a preset correspondence, and sending the transmit power of the WiFi antenna to the WiFi controller, wherein the transmit power of the WiFi antenna obtained by the first controller (105, 1051, 1052) is used to control, after the WiFi controller receives the transmit power of the WiFi antenna, the WiFi antenna to perform transmission according to the transmit power; and the determining, by the first controller (105, 1051, 1052), a service type of the WiFi antenna comprises: determining, by the first controller (105, 1051, 1052), that the wireless communications terminal performs voice communication by using the WiFi; and the wireless communications terminal further comprises an optical proximity sensor, and the method further comprises: determining, by the first controller (105, 1051, 1052), that the optical proximity sensor is triggered; and the obtaining, by the first controller (105, 1051, 1052), a transmit power of the WiFi antenna according to a preset correspondence comprises: obtaining, by the first controller (105, 1051, 1052), the transmit power of the WiFi antenna according to the preset correspondence, wherein the correspondence is used to determine, based on the case that the WiFi performs voice communication and the case that the optical proximity sensor is triggered, the transmit power of the WiFi antenna. determining, by the first controller (105, 1051, 1052), that the wireless communications terminal performs voice communication by using the WiFi; and the wireless communications terminal further comprises an optical proximity sensor, and the method further comprises: determining, by the first controller (105, 1051, 1052), that the optical proximity sensor is triggered; and the obtaining, by the first controller (105, 1051, 1052), a transmit power of the WiFi antenna according to a preset correspondence comprises: obtaining, by the first controller (105, 1051, 1052), the transmit power of the WiFi antenna according to the preset correspondence, wherein the correspondence is used to determine, based on the case that the WiFi performs voice communication and the case that the optical proximity sensor is triggered, the transmit power of the WiFi antenna. determining, by the first controller (105, 1051, 1052), that the optical proximity sensor is triggered; and the obtaining, by the first controller (105, 1051, 1052), a transmit power of the WiFi antenna according to a preset correspondence comprises: obtaining, by the first controller (105, 1051, 1052), the transmit power of the WiFi antenna according to the preset correspondence, wherein the correspondence is used to determine, based on the case that the WiFi performs voice communication and the case that the optical proximity sensor is triggered, the transmit power of the WiFi antenna.