Based on the bionic coupling theory, a kind of PDC cutter was designed according to the non-smooth surface structure of shells. In the design, the posterior slope and side rake angle were mainly considered, which have important influence on rock breaking efficiency. The bionic PDC cutters’ optimal installation angle in bit was theoretically analyzed and that in limestone drilling was further optimized by drilling test. The experimental results show that with the same rotating speed and weight on bit, the fastest rotating speed can be obtained with posterior slope 20° and side rake angle 0°. And the experimental results above may serve as a reference for PDC bit design, especially for the PDC drilling bit used in limestone stratum.