Abstract: With wide usage of PDC bit, downhole complex situations happen because the type of PDC bit is not suited to formation characteristic, or the quality of PDC bit is not good. In this paper, the complex situation of PDC bit broken off while drilling 311.2 mm hole to 2878.76 m in Well NP6-1 has been discussed, the fish of PDC bit is taken out of hole by using the taper tap machined as per the fish at the bottom of hole, and avoid losing money from well side track. The experience can provide a good reference to the same kind of fish accident or similar to fish accident.