Abstract: Marine ranching is an important part of China's marine economic development. This paper explores the technological innovation strategy of marine ranching based on the perspective of collaborative innovation network. From three dimensions of cooperation projects, patent applications and published papers, the paper selects the relevant data of China's marine ranching technology innovation collaboration from 2012 to 2021. First of all, based on the analysis of the existing collaborative network, the actor network theory is used to build the marine ranching technology innovation collaborative network, and the functions and roles of various actors in the marine ranching technology innovation collaborative network are analyzed; Secondly, the multi case study method is used to clarify the operation mechanism of the collaborative innovation network. The government policy promotion mechanism is the driving force for network expansion, the trust cooperation mechanism is the basis for the stable operation of the network, the interactive feedback mechanism is the way for the high-quality operation of the network, and the organization coordination mechanism is the guarantee for the stable operation of the network; Then, the UCINET software is used to analyze the data, calculate the network density, average path length, and the core edge structure evolution shape of the network centrality at each stage of the evolution of China's marine ranching technology collaborative innovation network, and make corresponding analysis. Using the UCINET software plug-in NETDRAW, the network evolution map of the five stages of China's marine ranching technology collaborative innovation network was drawn, and the characteristics of network evolution and the evolution of the relationship between actors were analyzed. Finally, the research conclusions and views of the paper are drawn. The study found that the overall number of technological innovation in the field of marine ranching is not large, and the main innovation subjects are mainly scientific research institutes, universities and high-tech enterprises. Take patent application as an example. At present, the research and development of a single institution is the main form, and the number of cooperative innovations is relatively low. The cooperation mode is mainly in the form of scientific research institutes universities and scientific research institutes scientific research institutes. Among the actors in the marine ranching technology innovation collaboration network, the government and leading enterprises are the core actors of the network, and universities, research institutes and technology suppliers are the indispensable main actors. Small and medium-sized enterprises in marine ranching can actively or passively join the network. In addition, various service institutions, enterprises and customers related to marine products, marine industry associations and public welfare organizations, media, etc. are common actors in the marine ranching technology innovation collaboration network. At this stage, the marine ranching technology innovation collaboration network is still in a period of rapid development and turbulence. Collaborative innovation has not been separated from the primary mode of government industry university research cooperation, and science and technology intermediaries, customers, industry associations, etc. are less involved. But on the whole, the number of network innovation subjects is still increasing, the network structure is becoming increasingly complex, the cooperation path within the network is becoming longer, and the cooperation accumulation of innovation subjects is declining. The current collaborative innovation network is low density. The research viewpoints in this paper can provide referential ideas and basis for major technological breakthroughs and research and development of marine ranching in the future, and help promote the technology supply of modern marine ranching construction, which is of great significance for the healthy development of marine ranching in China.