a model test tank, wherein the model test tank includes a first tank wall and a second tank wall that are arranged relatively to each other, and a front tank wall and a rear tank wall that are arranged relatively to each other; a through hole is disposed on the front tank wall; the front tank wall is connected with a front end of the first tank wall and the second tank wall; and the rear tank wall is connected with a rear end of the first tank wall and the second tank wall;

a bidirectional servo loading system, wherein the bidirectional servo loading system includes a horizontal loading module and a vertical loading module; the horizontal loading module being disposed on the rear tank wall and configured to apply a horizontal load to a test soil body piled up inside the model test tank; and the vertical loading module being located above the model test tank and configured to apply a vertical load to the test soil body;

a multi-scale model transformation system, configured to change a width of the model test tank, wherein the multi-scale model transformation system includes a plurality of retractable counterforce brackets; a width of the retractable counterforce brackets being constant and a side of the retractable counterforce brackets abutting against an inner inside of the first tank wall of the model test tank; the plurality of the retractable counterforce brackets being disposed side by side; and the retractable counterforce bracket being retractable and extendable along a length direction of the model test tank and being removable out of the model test tank through the through hole;

a sliding surface evolution visualization system, configured to record a whole evolution process of a landslide sliding surface evolution, wherein the sliding surface evolution visualization system includes a wall frame and a plurality of filming devices, the plurality of the filming devices being mounted in the wall frame in a matrix form, the wall frame is disposed in the model test tank along the length direction of the model test tank and an outer side of the wall frame is supported by an inner side of the retractable counterforce bracket;

a positive pressure monitoring system, configured to collect lateral pressure subjected by the test soil body during a test, wherein the sliding surface evolution visualization system includes a plurality of monitoring devices, the plurality of the monitoring devices being arranged in a matrix form and disposed on an inner side of the second tank wall;

an artificial rainfall system, wherein the artificial rainfall system is a rainfall device provided above the model test tank for simulating natural rainfall of different intensities; and

a control system, configured to control the bidirectional servo loading system, the multi-scale model transformation system, the landslide sliding surface visualization system, the positive pressure monitoring system, and the artificial rainfall system, and configured to monitor, collect, process, analyze, and display test data.