Abstract: Vacuum-surcharge preloading was adopted to deal with the soft foundation of a bridge and road connection section of a highway in Guangdong Province, during which an overall instability and slippage of the foundation occurred. In order to analyze the cause of subgrade slippage, based on engineering design, observation and investigation after glide, this paper made an analysis and calculation of the stability of land-slide body, it is concluded that the filling height of the embankment in the limit state is 4 m. The problems which need to be paid attention in the process of investigation, design, monitoring and construction were also discussed, which accumulate certain experience for stability control of applying vacuum-surcharge preloading to deal with soft foundation.