The invention discloses a device for reducing connecting rod slag inclusions. The device for reducing the connecting rod slag inclusions is applied to connecting rod fracture splitting machining equipment. The device for reducing the connecting rod slag inclusions comprises a vibration air cylinder and an oscillating bar mechanism, wherein the vibration air cylinder is connected with a vibration air circuit, the vibration air circuit comprises a logical switch circuit and an oscillating circuit, the connecting rod fracture splitting machining equipment loosens a bolt of a connecting rod in the final tightening process, the vibration air cylinder is switched into a vibration state through the logical switch circuit, the oscillating circuit drives the vibration air cylinder to vibrate, vibration of the vibration air cylinder is maintained for an oscillation period, the vibration air cylinder is switched into a stopping state through the logical switch circuit after the vibration air cylinder vibrates for the oscillation period, and the connecting rod fracture splitting machining equipment tightens the bolt of the connecting rod in the final tightening process; the oscillating bar mechanism is connected to the vibration air cylinder and vibrates along with the vibration air cylinder, and the oscillating bar mechanism drives a large head cover of the connecting rod to vibrate. The invention further discloses a method for reducing the connecting rod slag inclusions. By the adoption of the device and method for reducing the connecting rod slag inclusions, the slag inclusion problem occurring in a connecting rod machining process is solved, and the slag inclusion rate can be reduced by 60%.