Abstract: Uniaxial compression tests of hydrochemical eroded sandstone were conducted to study the mechanical properties and energy damage characteristics of sandstone subjected to hydrochemical erosion.The influence of hydrochemical erosion on the mechanical properties and damage forms of sandstone was analyzed,and the evolution of energy storage and dissipation of rock during loading process investigated.A rock ultimate energy storage model was proposed,and the rock damage evaluation index established.The results show that hydrochemical eroded sandstone trend to exhibit strain softening behavior and shear failure mode.At the beginning of loading,all external input energy is transformed into dissipation energy and mainly converted into elastic energy in the end.The stored elastic energy in the rock reaching its ultimate capacity is the main reason for its failure.The energy storage ulimateof rocks shows a non-linear correlation with the pH values of chemical solutions.D_E is suitable for evaluating the damage degree of hydrochemical eroded rocks under uniaxial compression.The research results provide a basis for stability assessment and safety evaluation of water-related rock engineering.