Jinshan gas field is located in Longfengshan structure and Changling fault depression; in the deep formations below Denglouku, drillability is poor with strong abrasiveness, which causes serious bit wear and inefficient use. On the basis of detailed and overall analysis on the adaptability of cone bit, PDC bit and impregnated diamond bit in high abrasive formation, an idea was put forward that by combining the technical advantages of high ROP of PDC bit and long footage of impregnated diamond bit, the design was carried out on PDC impregnated composite bit. Good effect is received in field application of the bit and reasonable suggestions are also put forward.