In this research, the optimization extraction technology of total flavonoids (TF) from walnut branch was studied by response surface methodology (RSM). And the scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical, total reducing power were researched to reveal the antioxidant activity of TF from walnut branch. Using total flavonoids content (TFC) as evaluating indicator, the optimum conditions for TF extraction were: solid-solvent ratio 1:25 (g/mL), extraction temperature 60°C, and ethanol concentration 70%. Under these conditions, the TFC was 12.97 mg/g (mg rutin/g). The antioxidant activity test showed that TF could strongly eliminate DPPH and hydroxyl radical, And had obviously total reducing power too. Then the conclusion could be drawn: optimization of TF extraction from walnut branch by RSM was reliable and the TF of walnut branch had strong antioxidant activity.