Abstract: To investigate the effects of twisted tape on heat transfer characteristics in helical tubes，a numerical study using water as working medium was carried out to investigate helical tubes with or without twisted tape under laminar flow，the enhancement on the heat transfer characteristics and the field synergy theory of twisted tape in helical tubes has been explored and analyzed.The results show that，as far as this study was concerned，the range of improvement on helical tube with twisted tape was 3.2-28.7%，when Re=34，it reached the maximum value of 28.7%；by comparison the field synergy number of two kinds of helical tubes，twisted tape enhanced the synergistic effect between velocity field and heat flow field.