Abstract: Coupled heat transfer (CHT) simulations taking account of transition flow around vane surfaces are carried out in this research. First, a coupled solver with finite difference method was developed to compute the heat transfer, and the direct coupling method was employed to combine the N-S equation solver in the flow passage and the heat transfer module in the solid domain. The modified Abu-Ghannam and Shaw (AGS) algebraic transition model was used to predict the transition flow around the vane surfaces. Then, coupled heat transfer simulation was carried out and verified through testing the 5411 run of NASA-MARKⅡ vane, a high-pressure turbine vane. The comparison between the numerical results and the tested ones has been shown that the AGS transition model is able to predict the transition model process in the boundary layer, and that the predicted vane thermal loads by such model are closer to the tested ones than those by full turbulence model. Finally the developed solver has been applied to the CHT simulations of a low-pressure air-cooled turbine with two cooling air channels and a slut in the trailing edge, and its vane thermal load could be analytically obtained.