Abstract: Two patterns of air plane engine inlet hot-air anti-icer are introduced in this paper,one is circumferential anti-icer,the other is double skin corrugated chord direction anti-icer.Based on the thermal analysis of the two anti-icers,the heat transfer performance and temperature field of ice protected surface are compared.The results indicate that the structure of frontal anti-icer affects anti-icing effectiveness obviously for a hot-air anti-icing system,the double skin chord direction anti-icer is more efficient,but under the normal conditions,a circumferrential anti-icer can attain the goal of ice protection and its structure is more simple,so it is more practical.