Chitin is a cost‐effective and abundant resource, enriched with nitrogen and oxygen elements, making it an ideal precursor for carbon‐based materials. However, traditional methods for preparing activated carbon from chitin often require substantial amounts of activators and complex carbonization processes, leading to suboptimal energy storage efficiency. This study presents a partial dissolution system achieved by modulating the mass ratio of chitin to activators (KOH and urea) and optimizing freeze‐thaw cycles. When chitin/KOH/urea is mixed at a 1:1:1.5 mass ratio and subjected to three freeze‐thaw cycles, the resulting porous carbon demonstrates a high specific surface area of 1783 m2 g−1 with significant N (4.75%) and O (11.16%) doping. The electrode achieves a specific capacitance of 309.1 F g−1 at 0.5 A g−1 in a three‐electrode system with 6 m KOH as the electrolyte. After 5000 charge–discharge cycles at 5 A g−1, the capacitance retention rate remains at 91.08%, indicating excellent cycling stability. When assembled into a symmetrical supercapacitor, it exhibits an energy density of 5.69 Wh kg−1 at a power density of 4996.1 W kg−1, demonstrating remarkable energy storage performance. This work introduces a novel method for preparing chitin‐derived porous carbon materials.