Abstract: The influence of structural parameters on the fluid flow and heat transfer characteristics in a pitted tube was studied using three-dimensional numerical simulation, while criterion formulae were fitted respectively for the heat transfer and resistance characteristics by multiple linear regression method. Results show that the periodic convex hull on the inner wall of tube has a good disturbance effect on the boundary layer near the wall, which improves the synergy between fluid velocity field and temperature field, thus enhancing the heat transfer effectiveness. Compared with smooth tubes, the Nusselt number (Nu) and friction resistance coefficient of a pitted tube could be respectively increased by 16%-40% and 15%-53%, while the comprehensive performance evaluation criterion (C_PEC) lies in 1.05-2.5. Compared with smooth tube heat exchangers, the relative heat transfer area of a pitted tube heat exchanger could be reduced by 10%-35%, when the heat transfer and fluid power consumption remain unchanged; the relative heat exchange capacity could be improved by 1.08-1.36 times, when the volume of heat exchanger and the fluid power consumption keep constant, in which case, the economical efficiency of the heat exchanger could be improved significantly.