Abstract: The flow and heat transfer characteristics of single-phase liquid sodium were experimentally investigated in a hexagonal 7-rod bundle channel with the velocity of 0-4 m/s, the heat flux of 0-120 kW/m² and the absolute pressure of 1.5-200 kPa. The corresponding Reynolds number ranges from 4 000 to 60 000, and the Peclet number varies from 0 to 340. The influence of some thermal parameters on the heat transfer characteristics of liquid sodium flow in a hexagonal 7-rod bundle channel was analyzed in depth. Empirical correlations of liquid sodium flow and heat transfer in a hexagonal 7-rod bundle channel were obtained by nonlinear regression analysis for experimental data. The results show that these correlations can accurately predict the friction coefficient and Nu in a hexagonal 7-rod bundle channel. The prediction error for flow and heat transfer is less than 5% and 6%, respectively. The new equation was compared with other results, and the error is within 30%. It is shown that the new empirical correlation is suitable for the flow heat transfer of liquid sodium in a hexagonal 7-rod bundle channel.