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.