Purpose/Significance To analyze the cost characteristics and applicable conditions of all-optical network(AON)in hospital settings，and to provide evidence for hospital network construction decisions. Method/Process A case study combined with cost analysis is employed in three hospitals located in eastern，central，and western regions in China. The 10-year construction and operation costs of AON are estimated. Under standardized assumptions，a model is constructed to compare the cost differences between AON and traditional net. work，and sensitivity analysis is applied to evaluate key influencing factors. Result/Conclusion Scale effect is existed in AON，and the cost advantage gradually emerges when the scale reaches 1 000 points or more. The network architecture should be reasonably selected in combi.nation with the hospital's scale，business needs and resource conditions to enhance the investment efficiency of network construction.