This paper describes the pollution condition and causes of the eutrophication of Shuanglong Lake prior to its management and introduces measures for comprehensive in situ repair (such as lake interception, ecological dredging, reoxygenation measures, slope care, ecological reconstruction and landscape restoration of the lakefront, later-stage management, and other measures). The study reports the effects of water purification after the implementation of these comprehensive in situ repair measures. The results show that these repair measures have been effective in controlling the eutrophication of Shuanglong lake, and this study therefore provides methods and technical reference for the management of urban lake eutrophication at home and abroad.