This paper inverts the chlorophyll a (Chl-a) concentration in the surface water of the Yellow River estuary and its adjacent seas based on the Geostationary Ocean Color Imager (GOCI) satellite remote sensing data, and verifies the GOCI data according to the measured Chl-a concentration in the surface water of the Yellow River estuary in 2019. The results show that the inverted Chl-a concentration is accurate. At the same time, through comparative analysis of the spatiotemporal variation characteristics of Chl-a concentration in the surface water of the Yellow River Estuary and its adjacent seas in the years with and without water and sediment regulation, this paper found that: First, in the years with water and sediment regulation, the Chl-a concentration continued to decrease from before the water and sediment regulation to the end of the water regulation period; from the beginning of the sediment regulation period, a large amount of sediment carrying a large amount of nutrients flowed into the study area in a short period of time, resulting in a significant increase in the Chl-a concentration in the sea area; second, the average concentration of Chl-a in the years with water and sediment regulation was generally lower than the average concentration in the years without water and sediment regulation, which indirectly indicates that water and sediment regulation caused a large amount of sediment to enter the sea, resulting in increased turbidity of the water body and reduced photosynthesis efficiency, which to a certain extent inhibited the outbreak of plankton, thereby preventing the occurrence of ecological problems such as red tides. In summary, the implementation of water and sediment regulation projects in my country has alleviated the siltation of reservoirs and riverbeds upstream of the Yellow River Estuary without causing damage to the ecological environment of the Yellow River Estuary Wetland and its adjacent sea areas. At the same time, the monitoring model constructed in this paper is of great significance.