Abstract: The damage and failure characteristics of deep rock are significantly different from those of shallow rock. Investigating the mechanical behavior of fractured sandstone under complex stress environments is crucial for ensuring the safe implementation of deep underground engineering projects. Taking sandstone samples with cracks of different angles as research objects, triaxial compressive mechanical experiments were carried out. The evolution law of the mechanical properties of the fractured sandstone foundation was analyzed, and the influence law of the crack on the mechanical properties of the sample was explored by means of the energy dissipation theory. The results show that the crack angle has little effect on the deformation and failure law of the sample, and the axial stress−strain evolution law of sandstone with different crack angles shows an inverted "V" shape, first increasing and then decreasing. The radial stress−strain curve increases at first and then decreases slowly. The post−peak stage shows a similar yield platform, with the maximum axial and radial strain being 0.86% and 0.32%, and the minimum strain being 0.37% and 0.19%, respectively. The axial deformation degree of the specimen is larger than that of the radial deformation, and the axial deformation degree increases with the increase of the crack angle. Both peak strength and elastic modulus exhibited linear growth with the increase of crack angle, the peak strength and elastic modulus of the sample increase linearly, but the increase amplitude decreases first and then increases. As the angle increases from 0° to 30°, 45°, 60° and 90°, the strength of adjacent samples increased successively in the latter compared with the former by 8.58%, 3.16%, 1.34% and 15.12%, and the elastic modulus increases by 5.46%, 0.07%, 3.13% and 3.74%. The changes of total energy, elastic energy and dissipative energy of different samples are basically the same. Energy analysis revealed consistent trends across specimens: total energy and elastic energy accumulated faster than dissipative energy, with rapid dissipation energy growth preceding failure. Defined energy parameters showed that the energy storage coefficient progressively increased (0.615, 0.618, 0.642, 0.662, 0.712) while the energy dissipation coefficient decreased (0.159, 0.153, 0.142, 0.139, 0.127) with the angle increases from 0°, 30°, 45°, 60°, and 90°. This inverse relationship demonstrates that specimens with higher strength possess greater energy storage capacity, reduced energy dissipation, and enhanced deformation resistance.