Amplified spontaneous emission (ASE) is an unavoidable effect in fiber lasers, which not only reduces the pumping efficiency of 1.5 μm laser, but also limits the power enhancement of 1.5 μm laser. In order to reduce the ASE noise energy in the output signal, a new fiber laser amplification system structure is proposed, based on the 1×2 AOM for signal optical cycling pumping amplification, and the simulation of continuous and pulsed signals is carried out using OptiSystem software. Compared with the pulsed fiber amplifier based on MOPA structure, the noise power decreases by 1.7 dB when the signal light is a continuous signal with a power of -30 dBm, and a pump energy of 350 mW, while the noise power decreases by 1.27 dB when the signal light is a pulse signal with a power of -30 dBm, and a pumping energy of 600 mW.