A mass of corrosion fissures arise during the washing process of rock salt cavern. In order to study the influence of fissures on the mechanical properties of salt rock, the mechanical properties of the cracked salt rock with different parameters were tested and studied by using MTS-815 rock mechanics test system. The test results were modified by logarithmic strain, the effects of fissules with different parameters on the strength and the deformation of salt rock were analyzed, and the energy characteristics in the process of the damage were analyzed based on the theory of energy dissipation. The testing results indicate that the peak strength of salt rock with different fissure angles are lower than that of intact salt rock, and the relationship between the reduction extent and the fissure angle isn't linear. The length of prefab fissure has obvious weakening effect on the peak intensity of salt rock. The longer the fissures are, the greater the weakening effect is. Most part of the total strain energy U produced by external force transforms into dissipated energy U_d, and a small part is accumulated as the releasable elastic strain energy U_e, which causes the damage and the plastic deformation in the salt rock. In the failure progress, the curves between energy, such as total energy consumption, dissipation energy and elastic strain energy, and strain present evident stage characteristics. The uniaxial compression of salt rock shows four stages: compression stage, elastic deformation stage, plastic deformation stage and failure stage.