In order to reduce the adverse effects of the preloading drainage consolidation on the surrounding environment, the concept of the lateral restraint of the surcharge preloading has been put forward. A preloading drainage consolidation model with the lateral restraint a variable has been established by using the finite element analysis software FLAC3D, followed by a comparison between the simulation results and the measured results of the surcharge preloading without the lateral restraint, which has verified the liability and feasibility of the numerical simulation model. An investigation has been made of the differences between the surcharge preloading with or without the lateral restraint. Experimental results show that the controlling of the lateral restraint helps to effectively reduce the settlement of the soft soil foundation and speed up the initial consolidation rate. Meanwhile the closer the position of the lateral restraint to the edge of the surcharge preloading area, the better the lateral confinement effect will be.