Estuarine coastal wetland ecosystems are vulnerable zones of the Earth’s ecosphere, and their vegetation responds sensitively to climate change. Vegetation phenology is a key component of global climate change research. However, due to the complexity and diversity of vegetation types and the influence of sea-land interaction, the phenology characteristics of vegetation in estuarine wetlands have received little attention. Therefore, we took the vegetation of the coastal wetlands of the Yellow River Delta (YRD) in China as the research object. Based on the year-by-year remote sensing classification of vegetation, the Gap Filling and Savitzky-Golay (GF-SG) algorithm was selected to fuse the 250-meter MODIS_NDVI with the 30-meter Landsat data based on Google Earth Engine. Double Logistic function (DL) was used to extract vegetation phenology parameters, and buffer analysis was used to analyze the spatial and temporal variation mechanisms. The results show that YRD is rich in vegetation species. In addition to agricultural vegetation, the main establishment species include Spartina alterniflora, Tamarix chinensis, Phragmites australis, and so on. The area of each vegetation type was characterized by interannual fluctuation changes. Vegetation phenology parameters, including Start of the growing season (SOS), End of the growing season (EOS) and Length of the growing season (LOS), showed interannual spatial differentiation patterns. The mean SOS of the five vegetation species showed a fluctuating downward trend, the mean EOS was more concentrated, and the LOS showed a decreasing and then fluctuating upward trend. Spatially, SOS and EOS showed a trend of advancement from the northeast to the southwest. Overall, the spatial pattern of vegetation phenology in YRD was obviously controlled by the sea-land interaction, showing a trend of gradual postponement from the inland to the ocean direction, but the change of LOS was not obvious.There was a significant seaward nature of vegetation phenology pattern in YRD.