Abstract: This paper mainly studies the relationship between water content and shear strength and shear strength parameters by direct shearing with undisturbed samples and remodeling samples. The research shows that shear strength decreases exponentially with the increase of water content and the relationship between water content and cohesion and internal friction angle can be expressed by exponential function in undisturbed samples. The influence of water content on cohesion is more significant than internal friction angle. Cohesion increases at first, then decreases with the increase of water content and internal friction angle is in a state of unstable fluctuation in remodeling samples. The conclusion has been applied to soft rock slope treatment in east slope in some open-pit coal mine.