The growth of zinc dendrites during cycling has constrained the development of the silver-zinc batteries. Herein, we focus on the practical application of polyethylene glycol with molecular weight of 200 as an electrolyte additive to the silver-zinc batteries. The cycleability of the batteries was significantly improved by introducing proper amount PEG-200 into the alkaline electrolyte. Further study shows that adding PEG-200 as electrolyte additive can effectively maintain the structure of the zinc electrode, and clearly inhibit the growth of zinc dendrites. At the same time, silver electrodes are not sensitive to the PEG-200 addition.