Embodiments of the present invention relate to the communication field and disclose a method and an apparatus for decreasing power consumption of a power amplifier, which minimize the power consumption of the power amplifier and extend the operation time of a mobile terminal. The method includes: obtaining a compensation power control value, where the compensation power control value is a power control value that is input to the power amplifier, and the minimum value of the input voltage is a minimum input voltage that can guarantee normal operation of the power amplifier when a preset power control value is input to the power amplifier; and inputting the minimum value of the input voltage and the compensation power control value to the power amplifier to control the power amplifier to output the preset power value of the antenna port.