The invention relates to a soil disintegration tester, comprising a scale, a blister, lead shots, a hanging frame, a screen, a glass container with a scale, and a soil sample, wherein a buoyancy device formed by connecting the scale, the blister and the scale is arranged into the glass container with the scale, the lower end of the scale is connected with the upper end of the blister, the hanging frame is tied on a connecting place between the scale and the blister, the blister is arranged into the hanging frame, the lead shots are arranged in the blister, the screen is distributed at the bottom of the hanging frame, and the soil sample is arranged on the screen. The soil disintegration tester, provided by the invention, has the advantages of simple structure, convenience for use and maintenance, and capability of accurately measuring three main disintegration indexes: a disintegration time, a disintegration characteristic and a disintegration speed. The soil disintegration tester can be widely applied to scientific studies about engineering geology and geotechnical engineering, teaching practice and production field.