Abstract: In order to study the influence of confining pressure to deformation and failure characteristics and energy evolution characteristics of phyllite, the conventional triaxial compression test is carried out with MTS815 servo-controlled rock mechanical test system. The results show the follows. As the confining pressure increases, the failure mode of phyllite changes from shear failure to mixed tensile-shear failure. The point k is the intersection of the curve of elastic strain energy and the curve of dissipation, before the k point of energy accumulation and after the k point of energy dissipation, respectively. In the early stage of loading, the curve of total energy and axial strain is concave curve, where the energy growth rate is to rise. In the later stage of loading, the curve of total energy and axial strain is convex curve, where the growth rate of energy reduces. At the point of peak strength, the total energy and energy storage limit has a linear relationship with the confining pressure. Confining pressure can hinder the crack propagation and energy release.