Abstract: Using real-time parameter database of online assistant decision-making system and pressure prediction software drillworks, combined with the comprehensive logging method and Dc index method, the formation pressure of the wells A, B and C has been monitored. Various parameters in the process of drilling can be display throughonline assistant decision system, which plays a very important role for qualitative judgment of whether entering the abnormal high pressure formation. Formation pressure monitoring results indicated thatthe formation pressuremonitoring accuracy is high using Dc index method.