We propose a method of cascading multiple nonlinear optical loop mirrors (NOLMs) in the laser cavity to enhance the single pulse energy in mode-locked fiber lasers. A geometrical description is used to engineer the transmittance curve of the effective mode locker in the cavity to enlarge the threshold of triggering multipulse transition. A full vector model of Ginzburg–Landau equation is adopted to model the pulse evolution in the cavity. Results show that, with the cascading NOLMs configuration, the single pulse energy and peak power can be increased by 170%–188% comparing with that in single NOLM cavity.