Abstract: To ensure the stability of the foundation pit excavation for a certain project on the soft soil foundation of tidal flats, the vacuum preloading combined with electro-osmosis method, which arranges conductive drainage boards and ordinary drainage boards at intervals, is adopted for reinforcement. The current, temperature, vacuum degree, surface settlement and pore water pressure in the soil were monitored on site, and the main property indicators of the treated soft soil were obtained through indoor geotechnical tests. Analysis shows that the vacuum preloading - electro-osmotic combined reinforcement method can promote the rapid drainage and consolidation of low-permeability tidal flat soft foundation. The physical and mechanical property indicators of the reinforced soft soil have been significantly improved, and the on-site excavation is smooth and the foundation pit is stable. Obvious thermal-temperature effects occur within the soil body and vary with the duration of electrification and the depth position. The moisture content has a very good linear relationship with the density, porosity ratio and compression coefficient. The internal friction Angle of the treated soft soil shows a significant correlation with the moisture content. The combined effect of electro-osmosis and vacuum can better enhance the friction characteristics between particles and improve the strength of the soft soil. After testing, the conductive plastic drainage board has stable performance and is not corroded. Based on the theory of porous media and the principles of saturated soil mechanics, a multi-field coupling numerical model of pore pressure field - electric field - seepage field - displacement field under the combined action of vacuum-electroseepage was established. The finite element software was used to simulate and study the variation laws of pore water pressure and displacement of soil. The calculation results were in good agreement with the measured data and could reflect the improvement process of the performance of soft soil under the combined action of vacuum-electroseepage.