Hierarchical mulberry-like iron-cobalt sulfide (Fe3S4/Co9S8) nanoparticles were conveniently fabricated through etching the FeCoAl alloy in mild conditions followed by one-step facile sulfurization process. The as-made sulfide nanoparticles are composed of interconnected tiny particles and numerous pore channels as the building subunits. Coupling with the hierarchical nanostructure and the synergistic effects between the dual sulfides, the Fe3S4/Co9S8 composite demonstrated the outstanding lithium storage performances in terms of superior reversible capacity, good rate performance, and exceptional cycling stability. The specific capacity of 945 mAh g−1 could be reserved over Fe3S4/Co9S8 composite at 100 mA g−1 after 100 cycles. More importantly, upon long-term cycles for 1500 loops under the high rate of 2000 mA g−1, the specific capacity of the as-made sulfide still retained as high as 519 mAh g−1. Fe3S4/Co9S8 composite presents prospective application potential in the field of energy storage technologies.