This research elaborates on the importance of developing port-related industries in port cities in light of the advantages of port resources. It also analyzes the concepts and types of port-vicinity industries in such cities. Moreover, utilizing input-output models, consumption coefficients, and other technical means, it assesses port-related industries’ scale, structure, and spatial distribution in port cities. A comprehensive evaluation system for port industries in port cities was established around four aspects: port transportation, port industry, port service industry, and the port-industry-city relationship. Fifty-nine port-city samples were selected for empirical analysis. The concepts, methods, and evaluation models in this study are highly significant for guiding port cities in choosing the development directions of port-related industries and determining their development goals.