China is one of the countries most seriously affected by the tropical typhoon disasters. Root pull-out and toppling damage caused by severe storms and rains occur frequently. Secondary disasters such as traffic disruption, vehicle damage and casualties are increasing. In order to investigate the effect of soil physical properties on the anti-overturning performance of trees, the pulling test of Ginkgo biloba seedlings under constant lateral loading rate was carried out through a self-designed lateral root loading test system to simulate the dumping process of roots under external load. Five sets of gradient water content and four buried depths were set to analyze the influence of soil moisture content and the root depth on the pull-out resistance during the pull-out process. The research indicates that in silty sand, the change of the anti-overturning force in the root displacement-drawing force curve can be summarized as three stages:gentle rise, steep rise and slowly rising to reach the peak. The anti-overturning force with the increase of moisture content showed the first rise. The overall trend of the post-fall is the same as the overall trend of the change of soil cohesion. When the moisture content approximates the saturated moisture content, the maximum anti-overturning force is significantly reduced. When the moisture content is constant, the maximum anti-overturning force of the root system increases linearly with the depth of the root system in the buried depth range set by the test.