When animals claws come into contact with hard objects,they can protect themselves from injury by adjusting their toe joint.Usually,this characteristic of animals is called self-adaptability.Inspired by this,a self-adaptive bionic PDC bit is designed.The bit can self-adjust the cutting teeths working angle according to stratas hardness so that it reduces the bits fracture and spallation causing by impact.The drilling rate of self-adaptive bionic PDC bit was compared to the conventional PDC bit whose caster angle is 15 and 20 degree respectively.