In order to explore the optimal extraction process,composition,and functional characteristics of phenols from R.occidentalis ,ultrasonic-assisted extraction of R.occidentalis phenols was carried out.The extraction process was optimized by a single factor combined with a response surface test with the extraction amount of total phenols and flavonoids from R.occidentalis as indexes.Meanwhile,the composition of the extract was determined by ultraviolet spectrum,infrared spectrum,and UPLC-Q-Exactive MS,and the antioxidant and antibacterial activities of the extract before and after purification were analyzed by the scavenging rate of DPPH and ABTS⁺ free radical and the size of inhibition zone diameter.The results showed that the optimum extraction conditions were as follows:material-liquid ratio 1∶26 (g/mL),ultrasonic time 47 min,ethanol content 57%,ultrasonic power 300 W,and ultrasonic temperature 60 °C.Under these conditions,the total phenols extraction yield reached 48.01±1.07 mg/g,and the total flavonoids extraction yield was 7.27±0.41 mg/g.It was found that a total of 17 polyphenols were identified.In addition,the extract showed great antioxidant and antibacterial activities,and the IC₅₀ values of DPPH and ABTS⁺ scavenging were 5.263 μg/mL and 11.61 μg/mL,respectively.When the concentration of R.occidentalis polyphenols extract was 40 mg/mL,the diameter of the inhibition zone against E. coli and S.aureus reached 18.73±0.19 mm and 16.97±0.12 mm,respectively. In conclusion,ultrasonic-assisted extraction can effectively promote the dissolution of phenols,and the R.occidentalis phenolic extract obtained by this method has good antioxidant and antibacterial activities.This study can provide a theoretical basis for the further processing and utilization of R.occidentalis resources.