Governments at all levels in China have developed a number of policies to guide, bolster and manage the offshore cage aquaculture since the introduction of this industry in the late 1990s. In this study, the evolution of 69 such policy documents issued since 1999 is traced out for the first time. Two time periods can be distinguished in offshore cage aquaculture in China: the Local development period (1999–2010) and the National development period (2011-present). The performance of the policy goals and objectives, the policy issuers, and the policy content are then examined through a combination of qualitative and quantitative analysis in order to figure out how the offshore cage aquaculture development philosophy has transformed, including its developmental ideas, directions, and focuses, all of which are manifested in the policy text. Under the guidance of the concept of sustainable development, the offshore cage aquaculture will play a more important role in the marine economy and impose new requirements on its policy environment in the future. Therefore, the formulation and implementation of policies have to be continuously improved to adapt to the development of offshore cage aquaculture. The following corresponding outlooks are proposed: (1) to expand the participation of formal policies with higher effectiveness, so as to secure long-term guidance; (2) to facilitate the involvement and communication of stakeholders; and (3) to improve relevant procedures and quantify the objectives, so as to better adhere to the goal of sustainable development.