Abstract: In order to investigate the qualitative and quantitative enhanced heat transfer of pipe inserted with twisted-tapes, we have established models for coaxial pipe heat exchanger using air as heat transfer medium and simulated.The simulation result is extremely consistent with the experimental results in the turbulence flow.It shows that heat transfer is better and coefficient of frictional resistance is bigger with the distort proportion smaller.The higher the fluid temperature, the more significantly radioactive heat transfer and the better heat transfer is.The effects of pressure on heat transfer is embodied in Re and Pr.