Abstract: To study and analyze the influence of thermophysical properties of each layer of rock on the overall heat exchange efficiency of tube bank area,a layered heat transfer analytical model of tube banks was built and verified,and regional thermal efficiency（ E_i）was put in as the evaluation index of heat transfer property of tube banks based on the finite long-line heat source theory,consideration of soil layer and conditions of tube banks. Comparisons were made with a homogeneous model of tube banks in respect of regional heat efficiency and temperature difference between inlet and outlet,and the results show that after operation for 2000 hours, E_i of the layered model was lower than that of the homogeneous model by 10.3%,and the decrease speed difference of E_i between the two models is approximately 6 times. E_i decrease results the reduction in temperature difference between inlet and outlet by 13% at most.Heat transfer analysis layer by layer of tube banks suggesteis that,with a fixed distance of 4 m,the heat exchange amount each linear meter of the soil layer with the largest thermal diffusion coefficient is reduced by 37.4%,while that of the layer with the smallest thermal diffusion coefficient increased by 0.32%. This shows that if heat exchanger of underground tube banks is to be set in layered soil with great difference in physical property parameters（especially thermal diffusion coefficient）,stratified analysis is needed so as to figure out the overall regional thermal efficiency of tube banks accurately.