As a pioneering field in marine resource development,deep-sea mining is progressively advancing from theoretical investigation into a stage of commercial exploitation.This study focuses on the economic analysis of commercial mining of deep-sea polymetallic nodules,and summarizes key components and methodologies for economic evaluations.A comprehensive and practical economic analysis framework has been established.Two representative international deep-sea polymetallic nodule mining projects have been selected for economic assessment and comparative analysis using the aforementioned framework.Through sensitivity analysis,the potential impacts of uncertainty factors on project economic benefits are evaluated,providing decision-makers with scientifically grounded support for investment decisions.