The structure and principle of the aircraft engine nose cowl thermal antiice（NCTAI）valve were introduced. Based on each component’s mathematical model, the whole model of the NCTAI valve was built in AMESim software. Taking an aircraft engine NCTAI valve as the object, the performances of the pressure regulator and the butterfly valve were simulated. The results show that the model meets the engineering requirements. The NCTAI valve typical faults of the plugged orifice caused by contamination were simulated and analyzed. The result shows that the plugged orifice may cause over pressure downstream the butterfly valve, and cause the system malfunction. This research conclusions can provide reference for airline company to maintain aircraft and for civil aircraft manufacturer to design related systems.