In order to determine the best extraction technology of polyphenol from Chrysanthemum morifolium Ramat.and evaluate their antioxidant activity, and analyze the chemical composition, SDS concentration, liquid-solid ratio, ultrasonic time and ultrasonic temperature as single factor were tested and then the extraction process of the polyphenol from Chrysanthemum morifolium Ramat.was optimized by response surface designs based on single factor experiments. In addition, the antioxidant activity of polyphenol from Chrysanthemum morifolium Ramat. was measured using the total reducing power, l1-diphenyl-2-picryhydrazyl radical (DPPH) and hydroxyl radical (OH) scavenging. The results showed that the polyphenol of optium extraction conditions of Chrysanthemum morifolium Ramat.were as follows: SDS concentration 1.50%, liquid-solid ratio 25 mL/g, ultrasonic time 24 min and ultrasonic temperature 65℃. Under these conditions, an extraction rate of 12.412 mg/g for polyphenol from Chrysanthemum morifolium Ramat.was obtained, compared with the predictive value of 12.59 mg/g, the relative error was 1.442%. The ED50 values of the total reducing power, scavenging OH radical were 9.00, 148.862μL, stronger than that of VC (20.00, 219.050μL) and BHT (415.00, 487.46μL); The scavenging DPPH radical (ED50 was 8.201μL) was weaker than that of VC, but stronger than that of BHT (ED50 was 86.06μL). The results of Chromatography analysis with HPLC show that isochlorogenicacid A, galuteolin, chlorogenic Acid, are the main components existing in polyphenols.The content of 3 respective components were 5.8704 3.1306 and 3.1025mg/g. The extraction process was stable and reasonable, accurate and reliable, and it can be used to extract the polyphenol from Chrysanthemum morifolium Ramat.The result will provide basis for the further development and utilization of polyphenols of Chrysanthemum morifolium Ramat..