Abstract: In view of the frequent occurrence of geological disasters such as slope debris flow and dangerous rock in the rock painting area of Helankou, through the detailed investigation and qualitative analysis of the disaster development characteristics and lithologic conditions in the region, it is concluded that the problem of frequent geological disasters is caused by the differential damage of thin and thick interbedded low-grade metamorphic sandstone. Based on previous research, freeze-thaw and dry-wet cycle experiments of two kinds of rocks in different chemical environments were set up, and the damage mechanism was preliminarily revealed. The results showed: The mass loss rate, the attenuation rate of cohesion and internal friction angle, the growth rate of the number and area of pores, the conversion rate of feldspar minerals, and the change rate of damage variable of thin low-grade metamorphic sandstone samples are significantly higher than those of thick low-grade metamorphic sandstone samples under any same deterioration conditions. The reason for the difference is that the thin low-grade metamorphic sandstone has a high content of feldspar minerals, the existence of latency layers, and interstitial material that is mainly argillaceous. The joint action of these three aspects makes the intensity of mineral hydrolysis and dissolution reaction and the degree of cementation failure of thin low-grade metamorphic sandstone significantly higher than that of thick low-grade metamorphic sandstone under the same deterioration conditions.