The designed construction of micro-/nano-structures and multi-composites on electrodes showed a promising prospect to improve electrochemical properties in supercapacitors. Herein, a facile carbonizing strategy was adopted for fabricating leaf-like CoSNC nanocomposites, which possess both the sheet structure and multi-composites of well-dispersed CoS2 nanoparticles in N-doped carbon frameworks. First, the leaf-like nanocomposites with high aspect ratios effectively shortened the ion/electron transmission paths and exposed more faradaic redox sites. Second, the N-doped carbon frameworks could stabilize the electrode structure during charge/discharge processes. Third, the well-dispersed CoS2 nanoparticles could also enhance the electrochemical kinetics. Hence, leaf-like CoSNC nanocomposites as electrode materials exhibited high specific capacitance, good rate capacity and cycling stability.