The work aims to study feasibility of response surface method in optimizing optimum chemical-milling solution formula of 2A97 Al-Li alloy. In traditional aluminum alloy milling of NaOH, Na2S, TEA and Al3+ solution system, effects of chemical-milling solution formula on surface quality of 2A97 aluminum lithium alloy, so as to optimize process parameters and obtain optimal chemical milling process. Based on single factor test, law of effects of chemical milling solution composition parameters on response value was obtained through regression analysis by performing Box-Behnken four design factors (NaOH, Na2S, TEA and Al3+) three level test in response surface method with surface roughness as response value. The optimum 2A97 Al-Li alloy chemical milling solution formula was obtained by optimization analysis. According to the test analysis of response surface design, when the 2A97 Al-Li alloy chemical milling solution formula was as follows: 130 g/L NaOH, 15 g/L Na2S, 50 g/L TEA and 70 g/L Al, the chemical milling solution was applied to chemical milling of 2A97 Al-Li alloy specimen, specimen surface was smooth and consistent, corrosion rate was 0.031 mm/min, surface roughness Ra=1.36 ?m, and free from pitting corrosion and intergranular corrosion. Fitting model coefficient R2=0.967 927 shows that the model is fit well, and response surface method is of certain reference value and can be used to analyze chemical milling process of 2A97 Al-Li alloy.