Throughout　the　evolution　of　supercapacitors,　binary　transition　metal　sulfides　have　been　extensively　researched　for　their　potential　as　electrode　materials.　Here,　NSAC-NiCo2S4　composites　are　prepared　by　in-situ　growing　NiCo2S4　nanosphere　on　N,　S　co-doped　activated　carbon　(NSAC)　using　a　simple　solvothermal　way.　The　optimized　NSAC-NiCo2S4　composite　inherits　the　NSAC＇s　huge　specific　surface　area,　hierarchical　porous　structure,　and　high　electronic　conductivity,　along　with　the　excellent　capacitive　performance　of　NiCo2S4.　This　combination　effectively　reduces　contact　resistance　and　enhances　the　transfer　rate.　Calculations　based　on　the　density　functional　theory　further　indicate　that　synergistic　interactions　between　NiCo2S4　and　NSAC　in　the　composite　lower　the　OH-　adsorption　energy　and　release　more　active　electrons.　This　enhancement　facilitates　the　electrochemical　reaction　kinetics　in　supercapacitors.　The　as-fabricated　NSAC-NiCo2S4-2　electrode　possesses　a　remarkable　specific　capacitance　(762　F　g-　1　)　at　1　A　g-　1　and　exhibits　a　minimal　charge　transfer　resistance　(0.28　Omega).　Furthermore,　an　asymmetric　supercapacitor　(positive　electrode:　NSAC-NiCo2S4-2;　negative　electrode:　NSAC),　achieves　an　impressive　energy　density　of　36.6　Wh　kg-　1　at　a　power　density　of　400.0　W　kg-　1　.　It　also　exhibits　exceptional　cycling　stability,　maintaining　86.2　%　of　its　capacity　after　10,000　cycles.　These　excellent　results　further　highlight　the　great　potential　of　the　obtained　NSAC-NiCo2S4　composites　for　use　in　energy　reserve　systems.