The present invention discloses a power head driving key sleeve device and a power head of a rotary drill. The driving key sleeve device comprises a driving sleeve and a driving key for cooperating with the drill pipe. The inner wall of the driving sleeve is provided with a plurality of mounting grooves extending along the axial direction thereof, and each mounting groove is provided with a driving key. Each driving key includes a first key body matched with the sliding gap of the mounting groove and a second key body protruding from the inner wall of the driving sleeve, The first key body and the second key body are arranged coaxially with the drive sleeve; Each drive key is fixedly connected with the drive sleeve through its corresponding upper and lower pressing plates. The driving key sleeve device of the present invention fixes the driving key strip by setting upper and lower pressing plates at both ends of the driving sleeve, which is conducive to the replacement and maintenance of the driving key strip of the power head; The power head of the rotary drilling machine of the invention adopts a new dovetail type key bar driving mode, which can further improve the efficiency and stability of product construction, and better create more profits for customers.