Abstract: Based on a reasonable hypothesis and according to the continuity equation, momentum equation, energy equation, boundary layer theory and relevant boundary condition, the mathematial model of heat transfer and fluid mechanics with fluid flowing through the heat pipe immersed in the packed bed is developed in this paper. After analogy transition and numerical calculation, the model is simplified and solved. In addition, convective heat transfer is measured experimentally with the fluid flowing through heat pipe immersed in the packed bed. After analyzing the experimental data, a heat transfer correlation is obtained. The experimental result is in agreement with the theoretical result while Re _d<500. The reason why there exists a great difference between the experimental result and theoretical result while Re _d>500 is discussed.