The extraction of the flavonoid from Pagodatree flower with water system and alcohol water backwatering system was studied. With water extracting method, the effect of temperature, pH value, and different technology was studied. With alcohol extracting method, through the orthogonal experiment, the optimum technical condition is obtained. The results showed that the optimum technology of extracting flavonoid from the Pagodatree flowers is B2C3A2, namely, 2 times volume 40% alcohol water, 3 extracting times (2 h/each time),and the content of flavonoid is 13.04%.