This paper selects 34 countries divided into four segments along the 21st-Century Maritime Silk Road as the research object，to analyze the development status of the Confucius Institute in the four segments and its influence on the enrollment of overseas students in China. It shows that firstly the development of Confucius institutes is very spectacular，the number of Confucius Institutes （classrooms） established by the Southeast Asian section is the largest，followed by the African segment. Secondly，the enrollment of overseas students to China has the characteristics of fast growth，large market potential，uneven distribution of each segment and large differences among countries. Thirdly，international reputation，teaching activities and cultural strength of Confucius Institutes affect the enrollment of overseas students in China. Based on the result the paper proposes that Confucius Institutes need to seize the policy advantages of the Belt and Road Initiative，develop the potential of students from countries along the 21st-Century Maritime Silk Road，and give full play to their role in promoting overseas students to study in China.