Under the action of water circulation，the sandstone foundation of inland port leads to the deterioration of rock mechanical properties and threatens the long-term stability of port foundation. In order to explore the mechanical characteristics and energy damage of sandstone under dry-wet cycle，we carry out the triaxial compression test under different dry-wet cycle times. The results show that with the enhancement of dry-wet cycle，the mechanical properties of sandstone gradually decay，the attenuation amplitude basically converges when the number of cycles reaches 15 times. The accumulation degrees of deterioration of sandstone peak strength，residual strength，elastic modulus and deformation modulus have the similar law，the accumulation rate of dry-wet cycle is faster when 0~8 times，and the accumulation rate slows down when 15 times. Under the action of stress，the total energy absorbed by rock increases with the increase of strain，and the accumulation of dissipated energy is mainly concentrated in the failure stage of rock. Energy dissipation leads to damage development，and the trend of damage variable and dissipated energy is consistent.