Abstract: Based on the economic data of land and sea in Shandong Province from 2001 to 2015, the paper analyzes and tests the relationship between land and sea economy.Granger test was conducted on the relationship between land and sea economy in Shandong province, then drawing the conclusion that there is a certain causal relationship between them.And the paper analyzes the relationship between marine economy and land-based three industries in Shandong province from 2001 to 2015 through gray relational analysis, then drawing the conclusion that Shandong province, marine economy Shandong province has the strongest correlation with the land-based secondary industry, followed by the tertiary industry of the land, and finally the first industry of the land.Finally, the paper summarizes the marine economic development of coastal cities in Shandong province and the economic relationship between land and sea, and draws the economic model of land and sea in seven cities along the coast of Shandong province.There are two economic models of land and sea that the land and sea simultaneously development, sea and land migration type in seven cities along the coast of Shandong province.Among them, Qingdao, Weifang and Weihai belong to land and sea simultaneously development.Yantai, Rizhao, Dongying and Binzhou belong to the sea and land migration type.In the sea and land migration type cities, Yantai and Rizhao belong to the marine economy dominated.However, Dongying and Binzhou belong to the land economy dominated.