In order to issue the problem of heavy damage of kernels during threshing corn ear, the bionic thresher was designed according to the excellent ability of beak inserting chink among kernels with low damage and the low cracked rate of differential thresh with bare hand. The thresher mainly includes discrete rod, threshing rod and differential rod. The correlative experiment of the bionic thresher and TY-4.5 thresher was done. As for the Zhengdan958 corn ear, the unthreshed grains rate of the bionic thresher was 0.30%, the cracked grains rate was 0.31%, and the corn cob was unbroken; the unthreshed grains rate of the TY-4.5 thresher was 0.29%, the cracked grains rate was 0.90%, and the corn cob was broken heavily. As for the Xianyu335 corn ear, the unthreshed grains rate of the bionic thresher was 005%, the cracked grains rate was 0.35%, and the corn cob was unbroken; the unthreshed grains rate of the TY-4.5 thresher was 0.09%, the cracked grains rate was 0.95%, and the corn cob was broken heavily. The results showed that the cracked grains rate of the bionic thresher was less than that of the TY-4.5 thresher under the similar unthreshed grains rate, and the corn cob was unbroken. The bionic thresher was suitable for threshing the seed corn ear.