Abstract: The multi-stage development strategy is often adopted in the gas field. However, when the productivity decline occurs, many large processing stations will be severely idle and underutilized, significantly reducing operating efficiency and revenue. This study proposes a novel operation mode of multiple gathering production systems for gas field multi-stage development, integrating the decisions about processing capacity allocation and infrastructure construction to share processing stations and improve multi-system operating efficiency. A multi-period mixed integer linear programming model for multi-system operation optimization is established to optimize the Net Present Value (NPV), considering the production of gas wells, time-varying gas prices, and the capacity of processing stations. The decision of processing capacity, location, construction timing, and capacity expansion of processing stations, as well as transmission capacity of pipelines and processing capacity allocation schemes, can be obtained to meet long-term production demand. Furthermore, a real case study indicates that the proposed processing capacity allocation approach not only has a shorter payback period and increases NPV by 4.8%, but also increases the utilization efficiency of processing stations from 27.37% to 48.94%. This work demonstrates that the synergy between the processing capacity allocation and infrastructure construction can hedge against production fluctuations and increase potential profits.