Abstract: Looking for high-performance and minimized heat exchange tube is one of the way for improving the performance of Once-through steam generator（OTSG）. This paper introduced the thermal-hydraulic experimental research on a new type heat exchange tube with internally revolved rib. The test system and the experiment model were presented. The heat transfer coefficient of the heat exchange tube and the influence of pitch on Nu were analyzed under different mass flow. The revolved rib showed a distinctive improvement on heat transfer performance under high Re condition, and minimizing the pitch was a good choice to enhance the heat exchange.