Since 2012，the scale of the marine economy in the eastern marine economic circle has always maintained a relatively rapid growth trend. Since the COVID-19 was gradually controlled in 2021，the gross ocean product of the eastern marine economy began to rise sharply，with an overall growth rate of 12.85%. From the absolute value of added value，the added value of the three marine industries in the eastern marine economic circle shows an increasing trend year by year. Since June 2021，Shanghai，Zhejiang and Jiangsu in the eastern marine economic circle have successively released the “14th five year plan” for marine or marine economy. The plan focuses on the high-quality development of marine economy，with many highlights. Through the method of cluster analysis，this paper classifies Shanghai，Zhejiang and Jiangsu in the eastern marine economic circle，and finds that within the eastern marine economic circle，the marine economic development of Zhejiang Province is relatively close to that of Jiangsu Province，which can be classified into one category，and Shanghai is another category. The introduction of The Outline Of The Yangtze River Delta Regional Integration Development Plan plays a very important role in promoting the coordinated development of the eastern marine economic circle. In order to better develop the marine economy of the eastern marine economic circle，it is suggested to take the Yangtze River Delta regional integration development strategy as an opportunity to optimize the structure and layout of marine industry，develop marine renewable energy industry，develop coastal tourism，improve the intelligent level of marine industry and guide the development of marine industry agglomeration.