In order to explore the evolution law of port economic hinterland under integrated development of regional ports，this paper studies Dalian Port and Yingkou Port before and after port resource integration and uses the improved hinterland plume model to calculate the scope of port hinterland in 2018 and 2020.Then，the paper draws the spatial distribution of simple and mixed hinterlands of each port by Arcgis software and analyzes the integrated development strategy for ports according to the evolution characteristics of port hinterland scope.The research results show that after port integration，the gap in the comprehensive influence between ports becomes smaller.The gap in the hinterland scope between Dalian Port and Yingkou Port decreases，and the scope of the mixed hinterland expands.Under the background of integrated development of ports，each port focuses on balancing and coordinating hinterland scope during development，so as to avoid homogeneous competition and realize reasonable division of labor.