Seeking organic cathode materials with low cost and long cycle life that can be employed for large‐scale energy storage remains a significant challenge. This work has synthesized an organic compound, triphenazino[2,3‐b](1,4,5,8,9,12‐hexaazatriphenylene) (TPHATP), with as high as 87.16% yield. This compound has a highly π‐conjugated and rigid molecular structure, which is synthesized by capping hexaketocyclohexane with three molecules of 2,3‐diaminophenazine derived from low‐cost o‐phenylenediamine, and is used as a cathode material for assembling aqueous rechargeable zinc ion batteries. Both experiments and DFT calculations demonstrate that the redox mechanism of TPHATP is predominantly governed by H+ storage. The Zn‐intercalation product of nitride‐type compound, is too unstable to form in water. Moreover, the TPHATP cathode exhibits a capacity of as high as 318.3 mAh g−1 at 0.1 A g−1, and maintained a stable capacity of 111.9 mAh g−1 at a large current density of 10 A g−1 for 5000 cycles with only a decay of 0.000512% per cycle. This study provides new insights into understanding pyrazine as an active redox group and offers a potential affordable aqueous battery system for grid‐scale energy storage.