It is far more difficult to reduce the temperature differences among cells in a battery module than to reduce the maximum temperature of module. In order that the cells can have better temperature distributing conformity, this paper designed a liquid cooling thermal management system by packing aluminum column in the gaps among the cells and set up an electrochemical-thermal coupling model for the cells. Comparative study of the impacts on the thermal properties of the cells exerted by liquid cooling system of aluminum columns under the combination modes of different entrance velocity，different section length and height was also conducted. The results indicated that the cooling performance of the aluminum column liquid cooling system with gradient variation of cross-section length and height and the temperature distributing conformity among the cells were better than those with the fixed values of section length and height. Under the condition that the discharge rate was 3C and the entrance velocity was 0.1 m/s，the maximum temperature difference among the cells in the module group based on the proposed coupling model was kept within 3.72 ℃，meeting the requirements of thermal management of the battery system. Finally, different discharge rates were verified through the simulation based on this model, indicating that the cells had better temperature distributing conformity.