Abstract: The purpose of the paper was to confirm orysan sativa containing hymecromone and to use the ultrasonic wave extraction in the total coumarin from orysan sativa trying to get the optimum extraction conditions.Hymecromone in orysan sativa was identified by TLC and HPLC methods. The extract rate and total content of coumarins as indexes, orthogonal experimental principle based on the single factor experiments was used to optimize the concentration of ethanol, the ratio of material to liquid, temperature and ultrasonic time. The results showed that hymecromone did exist in orysan sativa and the optimal extraction conditions of total coumarins of material were as follows: ethanol concentration 55%, solid-liquid ratio 1∶30, extraction temperature 70℃, extraction time 60min, power 96W. The conclusion had reached that the coumarins were mainly active ingredients in orysan sativa and the extraction process of total coumarins was stable and feasible, which had strong adaptability, high economic value and wide application prospect.