The invention discloses a locking type inner wall knocking drill with an adjustable air cylinder. The locking type inner wall knocking drill with the adjustable air cylinder comprises a fixing plate,wherein a support plate is arranged on the end part of the fixing plate; a lock seat is arranged on the support plate; a lock groove is formed in the lock seat; a support block is arranged on the lockseat; a clamping groove is formed in the support block; the air cylinder is arranged on the support block; a telescopic shaft is arranged in front of the air cylinder and is clamped into the clampinggroove; a telescopic block is arranged at the end part of the telescopic shaft; a lock shell is arranged on the locking groove; a connecting groove is formed in one side of the lock shell; the telescopic block is arranged in the connecting groove; butt-joint holes are formed in side walls of the lock shell; a guiding pipe is arranged on an outer side wall of the lock seat; a knocking shaft is sleeved in the guiding pipe; installation holes are formed in two sides of the lock seat and correspond to the butt-joint holes; the knocking shaft penetrates through the installation holes and the butt-joint holes; one end of the knocking shaft is a free end; and a drill bit is arranged at the other end of the knocking shaft. According to the locking type inner wall knocking drill with the adjustable air cylinder provided by the invention, an inner wall can be conveniently knocked through the drill bit of the knocking shaft, so that the knocking efficiency is greatly improved.