The invention discloses a novel highly-efficient high-power annular laser amplifier. The amplifier comprise four polarization reflection mirrors, four laser gain media, four lenses, two filtering hole stops, two electro-optical switches, one wavefront corrector and one reflection mirror. According to the invention, the amplifier is suitable for double-pulse direction transmission amplification and coaxial annular amplification of any transmission type gain medium, so energy storage and extraction efficiency of the laser gain medium is effectively increased and high-power laser output is acquired. Through the annular amplifier, annular amplification for any time can be achieved theoretically, quality of output light beams is effectively controlled and limitation on injected energy is loosened. Two space filters are adopted, so space modulation in the light beams can be effectively filtered. The image faces of the space filters are connected with object faces end to end, so diffraction effects of transmission in the cavity of the laser pulse can be restrained, and amplification with the high light beam quality is kept. The amplifier is of an annular structure, so the system structure is more compact.