Abstract: Based on the study that has been done, the slaking mechanism of red beds interaction with temperature, water and stress, was studied. Some results were obtained as following: (1) the engines of mudstone slaking are the difference value of stress, concentration, temperature, water pressure, atmospheric pressure, which were evoked by the change of the situation of red beds depositing; (2) the irreversible breaking of red beds' structures were induced by some physical chemistry processes related to water, temperature and stress, such as stress redistribution, solution, swelling, evaporation, capillary, seepage, erosion, et al.; (3) the structure breaking of mudstone was accumulated though the cycling between water and temperature and the seasonal cycling, until the structure destroy happened; (4) It is the difference value of factors that evoke various physical chemistry processes; then some stresses above and beyond the strength of mudstone were set up; the structure breaking are produced, until the rock fragment break away the rock mass though the cycling between water and temperature and the seasonal cycling.