On the premise of clarifying the related concepts of marine industry digitalization, the index system of marine industry digital level is constructed based on the "diamond model" and the projection tracing model is used to measure the digital level of marine industry in 11 coastal provinces and cities from 2014 to 2020; on this basis, the evolution law of the digital level of China marine industry is analyzed in depth. The research found that: the digital level of China's marine industry generally shows a rapid growth trend, however, there are some differences between the coastal provinces in different regions; Regional differences are the dominant factor for the regional differences in the digital level of China's marine industry during the research period. Among them, the northern coastal areas, the eastern coastal region has minimal internal variation, the internal differences in the southern coastal areas are in the middle; The digital agglomeration forms of marine industries in the three marine economic circles have their own characteristics: the coastal provinces and cities in the northern marine economic circle form "high-low" agglomeration type, the coastal provinces and cities in the southern marine economic circle form "low-high" agglomeration type, and the coastal provinces and cities in the eastern marine economic circle form "high-high" agglomeration type.