Based on a soft foundation treatment project in Hengqin, a plane finite element model was developed using ABAQUS software to simulate the step-by-step implementation process of the vacuum combined surcharge preloading method for soft foundation reinforcement. The influence of the spacing and depth of plastic drainage plates on the treatment effectiveness for soft foundations was analyzed, which served as a guideline for the design and construction of practical projects. The results indicate that both the distance and depth of the plastic drainage plates affect the effectiveness of vacuum combined surcharge preloading.