Abstract: The independent operation of container seaport cascading logistics subsystems affects overall efficiency. This paper proposes a collaborative optimization method for the coupling of logistics and energy in the cascading logistics of quay cranes and electric container trucks. A comprehensive electrical load model is developed for the container seaport's integrated loading, unloading, and material transfer subsystems. A sequential scheduling method for the subsystems and the energy system is proposed, yielding an optimization relationship for container transfer volumes in the cascading logistics. This enables sequential coordination between quay cranes and electric container trucks in terms of quantity distribution and operating speeds. Considering power balance and operational constraints of the logistics system, an integrated cascading logistics-energy collaborative optimization model is developed, with the objective of minimizing operational costs. The optimal sequential allocation ratio of quay cranes to electric container trucks is solved, based on which corresponding scheduling plans for cascading logistics and energy utilization schemes are developed. Using a seaport in Shandong as a case study, the results demonstrate that the proposed method reduces the operating costs of the seaport's energy system by over 2.62% without impacting ship scheduling plans, thus achieving synergistic and efficient operation of the cascading logistics-energy coupling system.