A method for enabling a power amplifier to support multiple powers includes: calculating a transmit power, according to RF parameters delivered by a baseband board, determining a power amplifier voltage according to the transmit power and a corresponding relationship between the transmit power and the power amplifier voltage, and adjusting a supply voltage of the power amplifier, according to the determined power amplifier voltage, so as to adjust an output power of the power amplifier. A RF module includes a conversion module that converts a baseband board signal into a RF signal, an antenna linear device, a storage module, a power amplifier module, an adjustable power module, and a power control module. A test method is employed to determine the relationship between a transmit power and a power amplifier voltage.