Abstract: In order to study and analyze water content affected to damage and degradation as well as a deformation and failure law of the argillaceous siltstone under condition of a high geo-stress, based on high surrounding pressure of 15, 25 and 35 MPa, a triaxial compression test was conducted on five different water content argillaceous siltstones with a dry, two natural water contents, natural water saturation and forced water saturation. A study was conducted on the rock with a water-rock interaction affected to the rock strength, deformation features, failure and damage. The study results showed that with the water content increased, the strength, deformation features and failure mode as well as the damage and degradation law of the argillaceous siltstone would be obvious. Based on a Weibull Distribution, with the application of the peak strength and elastic modulus, in combination with the relationship between the water content ratio and the rock damage constitutive model parameters,thus a statistical damage constitutive model to reflect multiple test curves was established. The established statistical damage constitutive model could be roughly fitted with the test curves and could well reflect the hydration damage and failure of the rock under the water-rock interaction and the condition of the high stress.