Hybrid rice seeds inevitably produced crackglume of rice husk during the maturation process, so the germination performance of appearing crackglume seed would be affected. These effects included seed vigor reducing, germination potential and germination rate decreasing and seedling quality lessening. So it is of great significance to distinguish and sort out the crackglume rice seeds from rice seeds during the producing and processing. In order to detect the crackglume rice seeds, the acoustic characteristics of the normal and crackglume hybrid rice seeds, which were fell at different drop heights and different spacing distances from tilt glass to microphone by using selfdeveloped acoustic detection devices, were tested. The experiment results manifested that voice voltage amplitude of normal hybrid rice seeds which impacted with glass plate was generally higher than that of crackglume hybrid rice seeds. Optimum drop height for hybrid rice seed was 150mm, optimum spacing distance from tilt glass to microphone was 10mm or 20mm, under maximum comprehensive identification rate condition. The comprehensive identification rate of Liangyou 108 hybrid rice seeds reached 94%, the comprehensive identification rate of Xin Liangyou 6380 and Liangyou 6326 hybrid rice seeds reached 88% and 92%, respectively. The average identification rate of normal, crackglume hybrid rice seed were 92% and 90.67% individually under optimum working condition. The crackglume rice seed could be separated effectively from normal rice seed by using impacting acoustic characteristics of rice seeds.