The structure and theory of engine nacelle anti-icing (NAI) system were introduced.According to the principle that the heat available should be larger than the heat required

the critical design point and required flows of NAI were determining by calculating the required bleed air at complete evaporation and running wet station respectively.The coefficient of water collection of NAI system was determined using Euler method based on the coefficient of water collection of wing and the data similarity rule.According to the theory of allowed maximum thickness of ice

the performance of NAI system was calculated using the VSAERO/ICE software.The result of simulation shows that the maximum thickness of ice can meet at the critical condition.