Abstract: The DC-side connecting cable was mainly applied in electrochemical energy storage systems, and its quality was related to the safety and reliability of the operation of the entire energy storage system. In this study, the temperature rise control problem of energy storage cables under long-term high-current operating conditions was investigated. A structural design limiting the surface temperature rise to no more than 45 ℃ was adopted, and special insulating materials with high thermal conductivity were selected. Key process controls for the insulation layer were implemented to achieve low thermal shrinkage. Consequently, low cable temperature rise and environmental adaptability were achieved. The developed DC-side connecting cable demonstrated significant temperature rise control effects under high-current conditions, meeting the engineering requirements for safety and reliability in energy storage systems.