The utility model provides an automatic cleaning device of engine crankshaft which the technical essential lies in: including conveyer belt, bent axle fixing base, the shower nozzle of giving vent toanger, air pump, position sensor and controller, the bent axle fixing base is placed on the conveyer belt, the top of conveyer belt is arranged in to the shower nozzle of giving vent to anger, and theshower nozzle of giving vent to anger passes through the outlet duct and connects the air pump, be provided with the backup pad on the support frame of conveyer belt under the shower nozzle of givingvent to anger, the top of backup pad makes progress to extend and crosses the conveyer belt and be provided with position sensor, position sensor connects the controller of locating the conveyer beltside, the air pump is connected to the controller. On laying the bent axle fixing base with the bent axle, then on discharging the conveyer belt according to the order of sequence with each bent axlefixing base, when the bent axle fixing base moved to the below of the shower nozzle of giving vent to anger, position sensor's detected signal was received to the controller to booster air pump work,and then give vent to anger through the shower nozzle of giving vent to anger and clear up the bent axle. The utility model discloses can clear up the bent axle, prevent that the king -bolt of bent axle is downthehole and have impurity.