<p>Metal–organic frameworks (MOFs) are prominent supercapacitor electrode materials by virtue of tunable pores and rich active sites. Introducing multi-heteroatoms has become a promising approach for enhancing the electrochemical properties of MOFs. Multi-heteroatomic MOFs have been constructed primarily via mixed-ligand strategies. The conventional mixed-ligand strategy is susceptible to ligand coordination dynamics and steric hindrance, resulting in low phase purity, poor crystallinity, and uneven distribution of active sites. Herein, a single-ligand multi-heteroatom approach is proposed to overcome these limitations. Cauliflower-like Ni-MOFs were synthesized using low-cost nickel nitrate hexahydrate (Ni(NO₃)₂·6H₂O) as metal precursor, and 3-amino-5-mercapto-1,2,4-triazole (AMT) acting as dual-heteroatom (N, S) ligand in a binary solvent environment composed of N, N-dimethylformamide (DMF) and ethylene glycol (EG). The coordination of N with Ni²⁺ and the O coordination centers provided by the binary solvent collectively reshape the d-<i>π</i> orbital hybridization between Ni and heteroatoms, significantly enhancing the energy storage efficiency of samples. Although the S atom in AMT did not directly coordinate, the lone-pair electrons of S could modulate the electronic structure of Ni²⁺ through weak intramolecular-induced dipole and non-covalent electrostatic effects. The optimal sample (N-5) as an electrode delivered a high specific capacitance of 1163 F g⁻¹ at 1 A g⁻¹ in 6&#xa0;M KOH electrolyte. Furthermore, an asymmetric supercapacitor (N-5//AC ASC) achieved a power density of 1014.72 W kg⁻¹ at an energy density of 24.89 Wh kg⁻¹. This study reports a single-ligand multi-heteroatom synergistic coordination strategy, offering a scalable route to advanced energy storage devices.</p>