The invention relates to a soil layer disintegration device under load effects in karst regions. The device includes a soil container, a first separating plate and a second separating plate. The soil container is made of organic glass and contains a soil sample. A jack applying pressure on the inner soil sample in the soil container is disposed on the soil container. The first and second separating plates are disposed in the soil container and at two sides respectively of the corresponding soil sample. The first and second separating plates form a first water tank and a second water tank respectively with the inside walls at two sides of the soil container. The soil sample in the soil container is provided with a first soil pressure detecting box, a second soil pressure detecting box and a pore water pressure gauge. Beneficial effects of the device are that soil layer disintegration under conditions of different vertical loads and different water levels and soil pressure changes in a disintegration process can be researched by the device; the soil container is made of an organic glass material, is resistant to acids and alkalis and is visual in a testing process; the device is simple to operate and can be used repeatedly; and the device can be dismounted after use to facilitate storage.