Three-dimensional numerical simulation was carried out for coupled flow and heat transfer of regenerative cooling channel and coolant in consideration of the cooling channel inflow and hot-gas wall nickelage.The empirical method was used to simulate hot-gas convective and radiative heat transfer;the coolant was methane

whose thermophysical properties varied with both temperature and pressure.The results show that

the secondary flow plus sudden expansion flow field at inflow could lead to increase of local pressure lose and affect the flow and heat transfer situation at a large downstream region;nickelage on hot-gas wall can improve its capacity to endure high temperature and reduce the copper-alloy temperature.