The invention discloses a deburring device for a pin tumbler hole of a lock cylinder. The deburring device comprises a rack as well as a movable frame, a guide rail, a power head, a support and a PLC (programmable logic controller) which are arranged on the rack, wherein the movable frame can slide horizontally on the rack under driving of a first cylinder; a metal cutter is arranged at the bottom of the power head; a lock cylinder clamp is arranged on the movable frame and located above the guide rail which is charged with negative electricity; an insulation frame for fixing the power head is arranged on the support and can move vertically on the support under driving of a second cylinder; the PLC controls the power head and the second cylinder according to a preset program. According to the deburring device, the lock cylinder is enabled to be charged with negative electricity due to the fact that the guide rail is charged with negative electricity, the PLC controls the metal cutter to move downwards to the position of the pin tumbler hole according to a preset program, and the metal cutter is contacted with the lock cylinder to be electrified; then the PLC controls the second cylinder and the power head to enable the metal cutter to move downwards rotationally to deburr the pin tumbler hole; when the metal cutter is worn seriously or broken off, the metal cutter reaching a preset position cannot be contacted with the lock cylinder and is not electrified, and the PLC controls the metal cutter to move upwards and controls an alarm to send an alarm until a new metal cutter is replaced and operation is started again.