To address the heat dissipation requirements of large-capacity energy storage battery packs, this paper takes a 587 Ah 1P104S energy storage battery pack as the research object and conducts thermal simulation analysis of a liquid cooling system. A three-dimensional thermal simulation model including cells, liquid cold plate, and thermal interface materials is established, and numerical simulation is performed under specified flow rate and inlet temperature conditions. Through analysis of the simulation results, the flow resistance characteristics and temperature uniformity performance of the current liquid cooling scheme are evaluated. Existing problems are identified, and targeted improvement directions are proposed from three aspects: flow channel topology optimization, flow distribution improvement, and heat exchange layout adjustment, providing a basis for subsequent structural optimization.