Soil load experiment model device with adjustable size and experiment method thereof

The invention provides a soil load experiment model device with an adjustable size. The device comprises a model slot for holding soil, a counterforce frame installed on the outer side of the model slot in a sleeving manner for reinforcing the model slot, and a load applying module used for applying a downward load to soil in the model slot; the model slot comprises two movable side plates; push-pull plates are connected into inner sliding cavities in a sliding manner; the counterforce frame comprises a movable side frame parallel to the movable side plates and a support plate; the movable side frame and the support plate are connected with a threaded telescoping mechanism; a stepping motor drives the threaded telescoping mechanism to rotate and flex, to adjust the position of the supportplate. According to the soil load experiment model device and the experiment method provided by the invention, the telescoping push-pull plates are arranged in the inner cavities of two side plates ofthe model slot, the size