The equalizing property of twin-core erbium-doped fiber amplifier has baan studied by establishing a theoretical model and numerically simulating the charaxteristics of the amplifier. The twin-core erbium-doped fiber amplifier can provide different gains for different channels and self-heal the extra channel loss between amplifying stages, thus equalizes the output signal level. The twin-core fiber amplifiers is very suitable for the multi-wavelength, multi-channal fiber networks.