The Pre-cutting bit is the first tool to contact and excavate the soil. It cuts a series of circular  rings along the radial direction of the tunnel face to loosen the soil in advance, which can  significantly improve the fluidity of the soil layer, reduce the cutting resistance of the scraper,  and provide favorable conditions for the scraper to cut and collect slag. This in turn enhances  the excavation efficiency and reduces damage to the scraper. The Pre-cutting bit exhibits  excellent adaptability in highly weathered formations and weakly cemented sandy gravel  formations.