With the promotion of the concept of sustainable development, the issues of aquatic ecosystem health attract substantial attention, and considerable work has been carried out on the health assessment of waters, e.g., rivers and lakes. However, the health assessment of offshore ecosystem is still at its exploratory stage. Based on the investigations on the related references at home and abroad, this paper analyzed the concepts of offshore ecosystem health assessment, summarized the main methods for the assessment, the principles for screening related indicators, and the research philosophy,  and systematically listed the quantitative indices for the assessment. Aiming at the main existing issues in the researches of offshore ecosystem health, the future research directions about the offshore ecosystem health were suggested. It was considered that the concept and connotation analyses, the screening of assessment indicators, the choice of assessment scale, and the integration of assessment methods should be further strengthened to improve the assessment of offshore ecosystem health.