In this study, based on the liquid cooling method, a confluence channel structure is proposed, and the heat generation model in the discharge process of three-dimensional battery module is established. The effects of channel structure, inlet mass flowrate, and coolant flow direction on the heat generation of the battery module were studied by control variable method. Simulation results show that the confluence channel structure (e) shows good cooling effect on the battery temperature when controlling the 5 C discharge of the battery module. In addition, compared with the straight channel under the same working condition. In the discharge process of battery module, average temperature amplitude in battery module decreased by 17.3%, the inlet and outlet pressure is reduced by 16.47%, and the maximum temperature amplitude is reduced by 20.3%. Effectively improve temperature uniformity and reduce pressure drop. The problem of uneven temperature distribution caused by uneven velocity distribution of coolant in traditional straight channel is improved. At the same time, the design of the confluence structure accelerates the heat transfer of the channel plate and provides a new idea for the design of the cooling channel.