Due to the excellent rheological properties, low porosity, low permeability, and self-healing characteristics of rock salt, utilizing salt caverns for compressed air energy storage (CAES) is an effective approach to improving the efficiency of renewable energy utilization. Considering the actual operating conditions of CAES systems, the surrounding rock of the salt cavern is subjected to discontinuous cyclic loading under different gas injection frequencies and pressures, leading to alternating creep–fatigue effects. This book combines theoretical analysis, experimental research, and model derivation to investigate the following aspects of rock salt mechanics under various conditions: Mechanical and damage characteristics under monotonic loading, Creep mechanical behavior under different stress levels, Fatigue failure characteristics under different loading rates, Fatigue mechanical properties under different low-stress intervals, Creep–fatigue mechanical behavior under varying high-stress interval durations, Creep–fatigue mechanical properties under different confining pressures. Additionally, acoustic emission devices were utilized to monitor and analyze the effects of stress levels on the evolution of creep–fatigue damage in rock salt. Long-term creep–fatigue experiments were conducted on rock salt at actual frequencies consistent with CAES operation. The reasons and patterns underlying the interaction of creep and fatigue under various conditions were analyzed. Based on these interactions, a state-variable-based creep–fatigue constitutive model for rock salt was proposed and validated.