The utility model relates to a nearly drill bit complex is fallen and is turned round brokenly rock device in oil and natural gas well drilling, prospecting, mine probing, the development of coal -bedgas equipment field. Mainly form by shell, mushroom head, by pass port, center pin, centre bore, gland, bolt, base, bearing, wing, spout, locating pin, spring. Nearly drill bit complex is fallen andis turned round brokenly rock device installs between bottom hole assembly and drill bit, utilizes drilling fluid pressure control wing to stretch out or retract and locking, along with the pilot bitwhile rotary cutting wall of a well. Nearly drill bit complex is fallen and is turned round brokenly rock device is shorter apart from the pilot bit distance, and broken rock load is little, and the operating efficiency is high, can satisfy the reaming hole technological requirement of deep well, ultradeep well and complex construction well, is favorable to the development effect of the deep oil gas of further improvement tibetan. Simultaneously, nearly drill bit complex is fallen and is turned round brokenly rock device still has simple structure, convenient operation, be convenient for installation, safe and reliable's advantage, the batch manufacture and popularizing and applying on a large scale be convenient for.