Abstract: Flow patterns of turbine blades such as the boundary layer will change with Reynolds number and then impact the heat transfer on the blade surface. This paper firstly analyzes the sensitivity of several factors in conjugate heat transfer (CHT) simulation combined with experimental data. On the basis, the influence of Reynolds number on the blade surface heat transfer is analyzed for a Mark Ⅱ blade. The results show that thⅡ e relevant parameters in CHT can significantly influence the accuracy of simulation; and the parameters selected for the Mark Ⅱ blade in the current paper are reasonable, which match well with the experiment data. The variation of Reynolds number cause the change of the blade boundary layer flow state and then significantly influence the heat transfer and temperature distribution on the turbine blade surface.