Abstract: Molten salts were used as the significant heat transfer and storage medium in kinds of high temperature industrial engineering. In order to explore convective heat transfer performances of solar salt with the subcritical water/steam, respectively, the heat transfer performance of solar salt with a high melting-point（220℃） in a horizontal double-pipe heat exchanger was investigated by using solar salt and subcritical water/steam as the working mediums. Based on the experimental data, a heat transfer correlation about the Nusselt number of solar salt was obtained by using multiple linear regression; the resulting Nusselt value was then compared to the values obtained via classical convective heat transfer equations. Results of the comparison suggested that the fitted Nusselt number correlation model was able to accurately describe the heat transfer between solar salt and subcritical steam/water within deviation of ±5%. Conversely, comparing the experimental results to those obtained via classical convective heat transfer equations, such as the Dittus-Boelter equation, Sieder-Tate equation, Михеев equation, and Gnielinski equation, yielded significantly large deviation（maximum:-20% to-40%）. Heat transfer of solar salt was found to be moderately affected by the inlet temperature, whereas the effects of the subcritical water/steam pressure within the inner pipe were minimal.