Abstract: To address the instability of excavation slopes in tidal flat soft clays of the Yangtze River Delta after conventional dewatering, this study implements and evaluates an integrated ground improvement technique combining vacuum preloading with electroosmosis. The aim is to enhance drainage consolidation and strengthen low-permeability soils to ensure excavation stability. In the field, electric vertical drains (EVD) and ordinary prefabricated vertical drains (PVD) are installed in an alternating layout. Throughout the treatment process, real-time monitoring is carried out on electric current, temperature, vacuum pressure, surface settlement, and pore water pressure. Laboratory geotechnical tests are also conducted to determine key physico-mechanical properties of the treated soil. The results indicate that the combined method significantly accelerates the drainage and consolidation of the soft clay. Engineering properties such as strength and stiffness are markedly improved, and the subsequent excavation is completed smoothly with satisfactory slope stability. During energization, a noticeable thermal effect is observed within the soil mass, with its distribution varying according to the duration of electrification and depth. A vacuum-electroosmosis multi-field coupled numerical model is established and analyzed using the finite element method, which reveals the evolution patterns of pore water pressure and soil displacement. The simulation outcomes corresponded well with field monitoring data, confirming the reliability of the proposed model in simulating the multi-field coupling processes involved in soft soil improvement. This study demonstrates that the combined vacuum and electroosmosis method is an effective solution for stabilizing tidal flat soft clays and provides a reliable numerical tool for predicting and optimizing similar ground improvement projects.