The invention discloses a multimode radio frequency power amplifier. The power amplifier comprises a common amplifier circuit for amplifying the power of an input radio frequency signal, a harmonic suppression circuit, a high-frequency-band common matching circuit, a high-frequency-band difference matching circuit and a low-frequency-band matching circuit, wherein the harmonic suppression circuit is connected with the input end of the high-frequency-band common matching circuit through a first switch and used for suppressing harmonic waves of signals at the GSM high frequency band or the TD-SCDMA frequency band; the high-frequency-band common matching circuit conducts impedance conversion matching on the received radio frequency signals at the GSM high frequency band, the TD-SCDMA frequency band or the LTE-TDD frequency band; the high-frequency-band difference matching circuit further conducts impedance conversion matching and / or harmonic suppression on the received radio frequency signals at the GSM high frequency band or the TD-SCDMA frequency band, and then sends the signals to a switch circuit; the low-frequency-band matching circuit conducts impedance conversion matching on the received radio frequency signals at the GSM low frequency band and sends the signals to the switch circuit. GSM, TD-SCDMA and LTE-TDD multimode radio frequency power is amplified with only one chip, circuit multiplexing and circuit sharing are used a lot, the integrity is high, the circuit structure is simple, and cost is low.