To solve the heat radiation problem of lithium ion power battery in the discharge process, a thermal model was established based on a ternary battery module. The rise of module temperature was simulated and analyzed experimentally under different discharge rates. The U-shaped liquidcooled pipeline was designed and the liquidcooled model of battery module was established by combining with the actual heat problem after verifying the accuracy of thermal model. The comparison was then conducted between different cooling mediums and different cooling temperatures to analyze the cooling performance of lithium ion battery module. The research shows that the U-shaped liquid-cooled pipeline can meet the cooling and heat dissipation requirements of battery module. Coolant with high thermal conductivity and low temperature has better cooling performance.