The paper aims to compare the activity dry and fresh Portulaca oleracea L. and their DPPH scavenging rates, and select enzymatic hydrolysate of Portulaca oleracea L. with high antioxidant activity as functional raw material to optimize the formulation of antioxidant beverage of Portulaca oleracea L.. Taking enzymatic hydrolysate of Portulaca oleracea L., stevioside and citric acid as independent variables and sensory score of beverages as response value, Box-Behnken response surface methodology are used to optimize the processing technology of antioxidant clarified beverage of Portulaca oleracea L. The content of polysaccharide and flavone in the enzymatic hydrolysate of fresh Portulaca oleracea L. is higher than that of dry Portulaca oleracea L, and the clearance rate of DPPH is also higher than that of dry Portulaca oleracea L.. Under the conditions of 45.2% of enzymatic hydrolysis liquid, 0.23 g/L of stevioside and 0.06 g/L of citric acid, the theoretical sensory score of Portulaca oleracea L. beverage is 33.2 points, and the actual score is 33.3 points. Its antioxidant capacity is good (the DPPH clearance rate is 34.6% when the beverage dosage is 0.60 mL). The predicted value of the regression model is close to the measured value, and the optimization of the processing technology of Portulaca oleracea L. antioxidant beverage by response surface method is reasonable and feasible. The prepared antioxidant beverage of Portulaca oleracea L. is wine red, clear and transparent, and suitable for sweet and sour.