Abstract: To adapt to the national energy security strategy, dual-carbon development goals, and diversified downstream coal market demands during the “15th Five-Year Plan” period, and to solve the industry bottleneck where traditional rigidly designed coal preparation plants struggle to resist multiple uncertainties from raw coal quality, market supply and demand, and capacity dispatching, this study systematically reviews the over 70-year evolution of coal preparation design relying on historical statistical data of domestic raw coal production and coal washing industries as well as current industry policy documents. Drawing on mature flexible production theory from manufacturing, three core supporting elements—raw material flexibility, process flexibility, and equipment flexibility—are proposed. A four-dimensional flexible design system is established, featuring flexible process systems, intelligent equipment layouts, diversified product structures, and agile operation and maintenance responses. Furthermore, an innovative “10-24-5” operation model is constructed for economic adaptability validation. The results show that under the rigid design model, coal preparation plants suffer from inherent drawbacks such as a lack of raw coal buffering and regulation capabilities, rigid process flows, and unbalanced equipment configurations. The three core flexible elements can achieve front-end buffering of raw coal fluctuations, modular reconstruction of separation processes, and adaptive intelligent control of separation equipment. The four-dimensional implementation pathways can synchronously achieve dynamic full-chain adaptation across production, equipment, products, and operation/maintenance. The “10-24-5” operation model can significantly boost the overall competitiveness of coal preparation plants in coping with external market and production fluctuations. Flexible design serves as the core pathway for coal preparation plants to achieve resilient, efficient, and sustainable operations during the “15th Five-Year Plan” period. By revising industry design standards, tackling key technologies in large-scale intelligent separation equipment, and constructing regional mega intelligent coal preparation demonstration projects, the coal washing industry can be driven to transition from a static production model characterized by fixed capacity and fixed products to a dynamic, market-driven value produc-tion model.