The steel body pdc drill bit with 5blades and 19mm cutters is suitable for soft, medium formation, such as clay, marl, lignite, sands, silt, anhydrite, etc. Balanced force design allows the bits suitable for down-hole motor application used in directional drilling with little radial vibration. The reasonable layout of patented pdc cutters in various structures at different locations endows the bits with strong aggressiveness and anti-abrasiveness. Strong aggressiveness allows the bits high rop. The simulation technology of dynamic flow field are used in hydraulic design to optimize down-hole flow field, beneficial to improve clearance speed and anti-balling simultaneously.