Liquid cooling is a mainstream heat dissipation method for lithium battery packs of electric vehicles at present, which can ensure that the battery can work safely within a suitable temperature range. A stamped double-channel liquid cooling plate was designed and analyzed, a computational fluid dynamics analysis model for the fluid domain of liquid cooling plate was then built, the mesh independence of model was further analyzed, and the method for reducing the pressure loss of liquid-cooling plate was finally discussed. Aiming at the uniformity of mass flow, the multi-field coupling integrated optimization software was used to automatically optimize the internal flow channel width of liquid cooling plate. In addition, the fluid-solid coupling heat transfer model was established to check the highest temperature and maximum temperature difference on the top surface of battery.