The invention discloses a silver nanowire etching solution and etching method. The etching solution comprises 1-30 parts of nitric acid, 1-30 parts of ammonia water, 60-95 parts of deionized water, 0.1-5 parts of preservative and 0.001-2 parts of surfactant. The etching solution disclosed by the invention can effectively lower the diameter of the silver nanowire, and can obtain the silver nanowire with smaller particle size by utilizing the silver wire surface reaction isotropy of the etching solution.