A method for reducing power consumption of a power amplifier of a communications device, wherein the method comprises: identifying, by a wireless communications module comprised in a communications device, when a Wireless Fidelity, Wi-Fi, mode of the communications device is already enabled, whether service data to be sent exists currently; acquiring, by the wireless communications module, received attribute information of the wireless communications module if the service data exists currently, wherein the received attribute information acquired by the wireless communications module specifically comprises: received signal strength indicator RSSI information and packet error rate PER information; determining, by the wireless communications module by using the received attribute information, a sending rate for sending the service data; and determining, by the wireless communications module according to the sending rate, a supply voltage value of the power amplifier connected to the wireless communications module, so that the power amplifier amplifies, according to the supply voltage value, a service request signal carrying the service data, wherein the determining, by the wireless communications module according to the sending rate, a supply voltage value of a power amplifier connected to the wireless communications module specifically comprises: acquiring, by the wireless communications module according to the sending rate, a modulation and coding scheme MCS index number that corresponds to the sending rate; acquiring, by the wireless communications module according to the modulation and coding scheme MCS index number, a rate grouping class to which the modulation and coding scheme MCS index number belongs; and determining, by the wireless communications module, a supply voltage value, which matches the rate grouping class, of the power amplifier by using the rate grouping class. identifying, by a wireless communications module comprised in a communications device, when a Wireless Fidelity, Wi-Fi, mode of the communications device is already enabled, whether service data to be sent exists currently; acquiring, by the wireless communications module, received attribute information of the wireless communications module if the service data exists currently, wherein the received attribute information acquired by the wireless communications module specifically comprises: received signal strength indicator RSSI information and packet error rate PER information; determining, by the wireless communications module by using the received attribute information, a sending rate for sending the service data; and determining, by the wireless communications module according to the sending rate, a supply voltage value of the power amplifier connected to the wireless communications module, so that the power amplifier amplifies, according to the supply voltage value, a service request signal carrying the service data, wherein the determining, by the wireless communications module according to the sending rate, a supply voltage value of a power amplifier connected to the wireless communications module specifically comprises: acquiring, by the wireless communications module according to the sending rate, a modulation and coding scheme MCS index number that corresponds to the sending rate; acquiring, by the wireless communications module according to the modulation and coding scheme MCS index number, a rate grouping class to which the modulation and coding scheme MCS index number belongs; and determining, by the wireless communications module, a supply voltage value, which matches the rate grouping class, of the power amplifier by using the rate grouping class. acquiring, by the wireless communications module according to the sending rate, a modulation and coding scheme MCS index number that corresponds to the sending rate; acquiring, by the wireless communications module according to the modulation and coding scheme MCS index number, a rate grouping class to which the modulation and coding scheme MCS index number belongs; and determining, by the wireless communications module, a supply voltage value, which matches the rate grouping class, of the power amplifier by using the rate grouping class.