Space division multiplexing is one of the main technologies to greatly improve the data transmission capacity of a single optical fiber. Few-mode erbium-doped fiber amplifier is essential to compensate for the transmission loss in long distance mode division multiplexing transmission systems. Therefore, obtaining equalization gain in all modes supported by few-mode erbium-doped fiber is vitally important, and the high differential modal gain will reduce the transmission performance of the system. In this study, 18 μm/124 μm few-mode erbium-doped fiber was fabricated by modified chemical vapor deposition technique, and a two-mode erbium-doped fiber amplifier based on the fiber was demonstrated experimentally. The gain is above 19.4 dB for LP₀₁ and LP_11a modes and its differential modal gain is lower than 0.66 dB between 1535 nm and 1560 nm when the LP_11b mode is pumped.