To further enhance the heat transfer capacity while maintaining the pressure drop of the cooling channels and gas wall temperature in control is one of the key technologies in the design of advanced expander cycle engine. Numerical simulation of inner wall heat transfer enhancement structure at the hot-gas side of thrust chamber and the cooling channel structure at the coolant side was made in this paper. The two structures are the most important ones which affect on the thrust chamber heat transfer. By analyzing the numerical simulation results of each structure, the inner structure with ribs which can enhance the heat transfer capacity of the thrust chamber reasonably and the structure characteristics which can improve depth-to-width ratio of cooling channel at the cylindrical section were obtained.