In order to improve the Rate of Penetration (ROP) of the glutenite formation in the Pearl River Mouth Basin (PRMB) Oilfields, the lithological characters of glutenite formation was identified by the X-Ray diffractometer. Laboratory experiments on core Uniaxial Compressive Strength (UCS), drill ability, and abrasive property were conducted to study their rock mechanics properties. According to the rock mechanics properties and the drilling data of the used PDC bit, the Polycrystalline Diamond Compact (PDC) cutters are optimized in terms of the bit crown, cutters distribution method, and hydraulic structure of the PDC bit. Comparing with the bits used in the adjacent wells, the drilling footage and the ROP of the optimized PDC bit are improve by 131% and 48%, respectively; and the drilling cost per meter is also reduced by 28%. The bit optimization method proposed takes the effects of the rock mechanics parameters, the drilling data of the used PDC bits, and the total property of all the bit parts into consideration and is simple and effective, which might be able to apply to the bit optimization of complex formation in the future.