Abstract: By using the grapefruit peel as the raw material, the ultrasonic-assisted extraction of pectin was carried out, and the effects of the solid-liquid ratio, pH value, ultrasonic time and acidolysis temperature on the yield of pectin were studied by using the single factor experiment and orthogonal experiment, in order to determine the best extraction technology of pectin from grapefruit peel. The results showed that the optimal extraction process of pectin from grapefruit peel was as follows:the solid-liquid ratio was 1:25, the acidolysis temperature was 80℃, the pH value was 1.5, and the ultrasonic time was 8 min. The yield of pectin was 12.56% under the optimal process conditions. The ultrasonic-assisted extraction of pectin from grapefruit peel could not only meet the growing market demands, but also greatly save the extraction time and improve the extraction rate of pectin.