In order to study the effects of dry and wet climate changes on the disintegration characteristics of argillaceous siltstones, the argillaceous siltstones of the Kinswat Water Conservancy Project in Xinjiang were studied. We conducted the experimental study on the indoor disintegration and mechanical properties of argillaceous siltstones with different degrees of weathering by indoor simulation of dry and wet watering change conditions. The results showed that as the degree of weathering intensifies, the resistance to collapse of argillaceous siltstone gradually weakened. After the cycle disintegration, the particle size content increased. The disintegration rate and disintegration amount of strong weathering were higher than that of the rock with low weathering degree. The weathering action promoted the change of the original structure of argillaceous siltstone and the increase of muddy matter content. It reduces the strength and ability to resist deformation. From the microscopic mechanism of disintegration, the content of clay minerals and the type of cement played a leading role in the occurrence of disintegration. Weathering promotes the increase of clay mineral content and accelerates disintegration. Different weathering types lead to differences in disintegration characteristics.