Abstract: An experimental device and method for simulating a subsurface erosion process is disclosed, including a constant-pressure water supply device, a subsurface erosion generator, and a water-soil collection device. The constant-pressure water supply device and the subsurface erosion generator communicate with each other by a pipeline. The constant-pressure water supply device is used to simulate a natural water flow in subsurface erosion. The subsurface erosion generator is used to carry sand and display the occurrence process of water-soil subsurface erosion. The water-soil collection device is used to collect soil and water loss data required for an experiment. In accordance with the experimental device, the water-soil subsurface erosion process can be accurately displayed, a water pressure can be adjusted as needed, and a height between the constant-pressure water supply device and the erosion generator can be adjusted to simulate the terrain.