In this article, the immersed lithium-ion battery module’s liquid cooling and heat dissipation scheme are studied, and the heat dissipation characteristics of the large-capacity battery module after the battery is grouped are analyzed. The simulation models of the liquid cooling system’s five inlet and outlet layouts are established. The numerical results show that immersed liquid cooling method can effectively prevent and reduce the temperature rise of large-capacity battery modules. The layout of the imports and exports can influence the heat transfer effect, which is of guiding significance for the design of immersed protective fluid heat dissipation of lithium-ion battery modules.