Citrus wilsonii Tanaka is a kind of medicinal citrus local variety in southern Shaanxi Province. It can be made into Chinese herbal medicine or soaked in water to treat gastric acid,bloating and dyspepsia. In order to provide theoretical basis for the development and utilization of Citrus wilsonii Tanaka resources,the ultrasound-assisted ethanol extraction technology and components of total phenol from Citrus wilsonii Tanaka were studied. Firstly,the five extraction parameters were investigated by single factor test and Placket-Burman design. Three factors with significant effect were selected as ethanol volume fraction,liquid-solid ratio and ultrasonic temperature. On this basis,the central composite design response surface method was used to further optimize. The optimal conditions were as follows:soaking time 15 min,ethanol volume fraction 44%,liquid-solid ratio 45.5 mL/g,ultrasonic time 20 min,ultrasonic temperature 34℃. Under the condition,the total phenol content per gram of Citrus wilsonii Tanaka lyophilized powder was 16.29±0.12 mg gallic acid equivalent. In addition,the results of HPLC showed that there were 18 kinds of phenols in the extract,including 4 kinds of flavonols,1 kind of flavanols,6 kinds of dihydroflavones,4 kinds of phenolic acids and 3 kinds of polymethoxyflavones. Naringin accounted for 91.36% of the total phenol.