Objective: To optimize ultrasonic extraction process of total alkaloids in Isatis indigotica. Method: With extraction amount of total alkaloids as index,effects of ethanol concentration,liquid-solid ratio,ultrasonic time on extraction technology was investigated by by L9(34) orthogonal test. Result: The influencing order of each factors on ultrasonic-assistant extraction process of total alkaloids was ethanol concentration>extraction time>liquid-solid ratio. Optimum extraction process was as following:extracted 20 min with 10 times the amount of 80% ethanol. Conclusion: This optimized technology was stable and feasible with high extraction rate.