Testing device and method for researching mechanical properties of root-unsaturated soil interface

The invention relates to a test device and method for researching mechanical properties of a root-unsaturated soil interface, and the device is characterized in that a drawing system is connected with a pressure chamber system, the pressure chamber system is used for placing a root-soil composite sample, and the drawing system is used for fixing a root system of the root-soil composite sample and drawing the root-soil composite sample; the sample matrix suction control system is connected with the pressure chamber system, and the sample matrix suction control system is used for adjusting the saturation of the root-soil complex sample; the automatic confining pressure-water supply system is connected with the pressure chamber system; the automatic confining pressure-water supply system is used for providing confining pressure for the root-soil complex sample and simulating the stress state of the root-soil complex sample; when the sample matrix suction control system and the automatic confining pressure-water