Pulse-amplitude equalization through a nonlinear-amplifier-loop mirror in active rational harmonic mode-locked fiber laser is designed and experimentally demonstrated. An optical pulse train with a high repetition rate is generated when the modulation frequency is tuned to a rational number of the cavity's fundamental frequency of the fiber laser. Through incorporating a nonlinear-amplifier-loop mirror into the cavity, the pulse train can be equalized by adjusting the DC biased voltage and the modulation depth. At the modulation frequency of 1 GHz, an amplitude-equalization pulse train with repetition rate of 4 GHz or 5 GHz is obtained.