The invention provides an intelligent drilling expert system. The intelligent drilling expert system comprises a field sensor detection system, an intelligent expert system and an execution mechanism. An automatic closed-loop drilling regulation and control system is formed. Data in a whole drilling process are acquired through a field sensor; then, the acquired data are transmitted into a computer for processing, monitoring, prediction, analysis, explanation, control and the like. Most importantly, through the researched cross-specialty and cross-industry intelligent expert control models for drilling hydraulic control, well wall stability control, friction resistance and torque control, drilling speed and cost control, drilling complexity and accident control and the like, instantaneity, early discovery, early prediction, interpretation while drilling and an automatic control function can be realized, and accurate information is provided for drilling engineering; moreover, the intelligent drilling expert system has the advantages of reducing the drilling cost, increasing the drilling speed, avoiding sudden accidents and discovering oil and gas accurately.