Logistics parks are the inevitable outcome of modern logistics industry development to a certain stage. Rational planning and effective use of logistics park land can improve the operational efficiency of ports, reduce logistics costs, and enhance the competitiveness of ports. Port logistics parks play a significant role in improving port functions, enhancing the level of port operation organization, and expanding the port’s radiation service capacity. Due to the many factors involved, determining the scale of port logistics parks is a complex task. In the context of the current scarcity of land resources, reasonably determining the scale of the port logistics park reasonably is very necessary. This paper combines three models—the analogy model, land use intensity model, and space–time consumption model—into a new model. These three models have their own shortcomings, which we aim to avoid through their combination. The new model is applied to calculate the scale of a port logistics park, with Xiamen Haicang Port as a case for actual verification. In 2035, the container throughput of Xiamen Haicang Port will reach 14 million TEU, and the required scale of the port logistics park is 3.2 km2. The scale of the port logistics park aligns with the planning requirements. Practice has proven that this method is feasible for calculating the scale of logistics parks.