Abstract: In offshore cage aquaculture, the fouling organisms attached to netting could be detrimental to cage facilities and the living environment of cage-cultured fish. Due to the wide variety of marine fouling organisms, the various changes in the marine environment, the complex structure of net cage, the safety of farmed fish, and the varying conditions of farmers, the anti-fouling work of net cage is very complicated and difficult. Therefore, the antifouling problem of netting has been a cause for concern in offshore cage aquaculture. This paper briefly introduces the classification and the product characteristics of offshore cages; based on these, it then specifies the cutting-edge of offshore cage antifouling technologies, including manual cleaning method, antifouling coating method, mechanical cleaning method, metal alloy netting antifouling method, box rotation antifouling method, biological antifouling method, and the intrinsic antifouling method of netting, etc. Meanwhile, the antifouling effects of these methods, particularly the good and bad effects compared with manual removal method, are summarized. Underpinned by our research group’s findings regarding cage antifouling, it analyses the different methods listed above and serves as reference for in-depth study of offshore cage antifouling technologies and green development of offshore cage aquaculture. On the basis of summarizing some cage antifouling methods with their advantages and disadvantages, the authors proposed some research proposals directions for cage antifouling technologies. The first is to study the antifouling mechanism of net coatings and metal alloy net, the intelligent technology of the mechanical cleaning machine and the spinning technology for composite fiber with the intrinsic antifouling function. And the second is to create collaborative anti-fouling technology (such as the combination of mechanical removal method and antifouling coating method or other antifouling methods). In China, there is great potential in offshore cage aquaculture, but there is a long way to go in the study of antifouling technologies of offshore cage netting.