By using the computing platform MSC. Marc, a finite element analysis model has thus been established of the three-dimensional overall structure, followed by a numerical simulation calculation conducted on the seismic isolation effect of geo-bags, as well as a study on the influence of rubber sand ratio in geo-bags and the height of geo-bag isolation layer on the seismic isolation effect of superstructure. However, the isolation effect is weakened with the continuous increase of rubber content. It is found that the optimum mix proportion of rubber particles as isolation material is 30%; with the increase of the thickness of the geo-bag isolation layer, it is characterized with a more obvious isolation effect. However, with the project cost and other factors taken into consideration, the optimal height of the geo-bag isolation layer under this experimental condition is 500 mm. This study shows that, as a new type of base isolation method, the geo-bag rubber sand isolation layer is characterized with such advantages as good isolation effect, low cost and environmental protection, which is suitable for houses in villages and towns with a low construction cost.