The invention relates to a double-ring feedback gain flattening erbium-doped optical fiber amplifier and belongs to the technical field of optical fiber amplifiers. The double-ring feedback gain flattening erbium-doped optical fiber amplifier structurally comprises a basic amplification optical path, a first three-port circulator (13), an optical fiber loop mirror (14), a second three-port circulator (15), a grating (16), a fourth optoisolator (17), an optical attenuator (18), a photoelectric converter (19), a PID control circuit (20) and a voltage-controlled current source (21), wherein the basic amplification optical path is composed of a signal source (1), a first optoisolator (2), a first coupler (3), a first wavelength division multiplexer (4), a first erbium-doped optical fiber (5), a second wavelength division multiplexer (6), a second optoisolator (7), a gain flattening filter (8), a second coupler (9), a second erbium-doped optical fiber (10), a third optoisolator (11), a first optical splitter (12) and a pumping module (22). The double-ring feedback gain flattening erbium-doped optical fiber amplifier has the advantages of being flat in gain, high in responding speed, controllable in output power and the like.