Abstract: The rotary percussion drilling technology can effectively solve the problem of hard rock drilling, and the percussion device is the key equipment of the rotary percussion drilling technology. In view of the various problems existing in the use of the current hydraulic impactor, the paper studies a new type of gravity impactor which converts the rotation of the drill pipe into the reciprocating movement of the hammer in the vertical direction. In this paper, the working principle, design of key components and important performance parameters of the new type of gravity impactor are discussed in detail. The new gravity impactor has the advantages of simple structure and strong adaptability to complex environment, and overcomes the problem of the failure of the hydraulic impactor due to the failure of the vulnerable components.