In the present study, the extraction efficiency of flavanones and methoxyflavones has been investigated with respect to four parameters including solvent concentration, temperature, time, and solid-liquid ratio. Water precipitation method was used to enrichment total flavonoids of sweet orange peel extract and also evaluated the antioxidant activity. Results show that the mainly flavonoids of citrus peel were flavanones and methoxyflavones; there was a significant difference between the regularity of the change in the content of the flavanones and methoxyflavones with the same extraction factor. The optimal extraction of flavanones were: 70% ethanol concentration, solid-liquid ratio of 1:20, 90℃ extraction 4 h, the content of total flavanones can reached 24.74±0.42 mg/g；the optimum condition of methoxyflavones were determined as follow: 80% ethanol concentration, and solid-liquid ratio of 1:10, 60℃ extract 2h, the yield of total methoxyflavones was 2.83±0.08 mg/g. Water precipitation method was used for enrichment sweet orange peel flavonoids extracts by removing sugars, organic acids, pigments and other impurities. After purification, the extraction yield of flavonoids was increased from 12.34% to 42.05%. 2, 2-diphenyl-1-picrylhydrazyl radicals (DPPH), and 2, 2′-azino-bis (3-ethylbenzthiozoline-6)-sulphonic acid (ABTS) methods were used to evaluate oxidation abilities demonstrated that the antioxidant capacity had highly correlated to the total content of flavonoids in the extracts.