Abstract: Power-to-hydrogen (P2H) technology is a crucial technique for achieving the carbon peaking and carbon neutrality goals and decarbonizing electricity. Due to the limitations capacity in alkaline electrolysis cell (AEC), P2H plants/stations utilize the inherent scalability of AEC to form large-capacity multi-electrolysis cells cluster system. However, according to existing research on dispatch operation frameworks, it is hard to ensure the optimal performance of cluster system. Therefore, a dispatch operation framework for P2H multi-electrolysis cells cluster system that considers efficiency optimization models is proposed, aiming to enhance system efficiency and optimize the power distribution among AECs. Firstly, the effects of temperature and loading rate on the efficiency of hydrogen production are analyzed, and an efficiency optimization model for P2H including auxiliary systems is established. Based on this, an efficiency optimization model for cluster system is constructed, in which the process is linearized into a mixed-integer programming problem to solve for the power distribution of each AEC under the optimal efficiency; moreover, an optimization scheduling framework for P2H cluster system is proposed. Finally, case studies are analyzed based on the IEEE 33-node distribution network system. The results show that the proposed dispatch operation framework can reduce system operating costs, enhance system hydrogen production efficiency, and increase hydrogen production. The research findings can provide references for the efficient and economical operation of P2H multi-electrolysis cells cluster system.