SOpen caisson is a common construction method of pump stations, which has the advantages of low investment and short construction period. However, its application in the central urban area of Shanghai has gradually decreased in recent years because of its great impact on the surrounding environment in the sinking process. This paper aims to introduce a several protective measures for the surrounding environment under complex conditions of soft soil area conducted successfully in the case of an open caisson project of the initial rainwater upgrading pumping stations located in Hongkou District of Shanghai. These scientifically and reasonably organized measures can provide reference for other open caisson construction under similar conditions.