A three-dimensional coupled numerical simulation method was applied to simulate the performance of an engine lip electro-thermal anti-icing system at different conditions. The balance temperature of engine lip surface and the dynamic response time of surface temperature rise were obtained to estimate the performance of the anti-icing system. The simulated results were compared with experimental results in icing tunnel. And based on the comparison,simulated results were corrected. The study showed that the balance temperature of engine lip heating surface was above 273.15 K and the dynamic response time was less than 60 s,indicating that this anti-icing system could meet the requirement,and the severe anti-icing conditions were mainly those with higher flight speed and lower ambient temperature. And after correction the simulation coincided with experiment. The results can effectively guide the engineering development and provide a reference to improve the accuracy of anti-icing simulation.