Human activities have significantly impacted the tidal flat of the Yangtze River delta over the past 30 years. The construction of dams and coastal engineering projects have influenced the growth of the tidal flat. The area growth rate of the tidal flats varied over time, with a decrease in growth rate initially due to decreased sediment flow into the sea, followed by an increase in growth rate attributed to large-scale engineering projects. Tidal flats above 5 meters were more sensitive to sediment changes compared to those at sea level. The study highlights the complex relationship between human activities and the evolution of coastal areas.