Dendrite growth and side reactions of the Zn metal anode limit the cycle life of aqueous Zn batteries. Herein, we propose a sodium dichloroisocyanurate electrolyte additive with a low concentration of 0.1 M to modify the Zn interface environment and construct a stable organic-inorganic solid-electrolyte interface on the Zn electrode. It suppresses corrosion reactions and directs uniform Zn deposition. The cycle life of the Zn electrode in symmetric cells extends to 1100 h at 2 mA cm-2 and 2 mA h cm-2, and the Zn plating/stripping coulombic efficiency reaches 99.5% for more than 450 cycles.